Fix examples. (#102)

* Fix ex2 and ex4 builds
* Update unsupported target SDK version.
* Update usage of deprecated API of instrumentation registry.
* Update apk path in tutorial.
diff --git a/examples/ex1_standalone_app/build.gradle b/examples/ex1_standalone_app/build.gradle
index 1825c7e..eed268a 100644
--- a/examples/ex1_standalone_app/build.gradle
+++ b/examples/ex1_standalone_app/build.gradle
@@ -6,7 +6,7 @@
     defaultConfig {
         applicationId "com.google.android.mobly.snippet.example1"
         minSdkVersion 15
-        targetSdkVersion 22
+        targetSdkVersion 26
         versionCode 1
         versionName "0.0.1"
     }
diff --git a/examples/ex2_espresso/README.md b/examples/ex2_espresso/README.md
index 03973d1..b43507a 100644
--- a/examples/ex2_espresso/README.md
+++ b/examples/ex2_espresso/README.md
@@ -111,7 +111,7 @@
 
 1.  Install the apk on your phone
 
-        adb install -r ./examples/ex2_espresso/build/outputs/apk/debug/ex2_espresso-snippet-debug.apk
+        adb install -r ./examples/ex2_espresso/build/outputs/apk/snippet/debug/ex2_espresso-snippet-debug.apk
 
 1.  Use `snippet_shell` from mobly to trigger `pushMainButton()`:
 
diff --git a/examples/ex2_espresso/build.gradle b/examples/ex2_espresso/build.gradle
index 64dcdc6..9caf136 100644
--- a/examples/ex2_espresso/build.gradle
+++ b/examples/ex2_espresso/build.gradle
@@ -18,6 +18,7 @@
             dimension "examples"
         }
         snippet {
+            testApplicationId "com.google.android.mobly.snippet.example2.snippet"
             dimension "examples"
         }
     }
diff --git a/examples/ex2_espresso/src/snippet/AndroidManifest.xml b/examples/ex2_espresso/src/snippet/AndroidManifest.xml
index 95ee221..85797ce 100644
--- a/examples/ex2_espresso/src/snippet/AndroidManifest.xml
+++ b/examples/ex2_espresso/src/snippet/AndroidManifest.xml
@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<manifest xmlns:android="http://schemas.android.com/apk/res/android"
-    package="com.google.android.mobly.snippet.example2.snippet">
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
 
     <application>
         <meta-data
diff --git a/examples/ex3_async_event/build.gradle b/examples/ex3_async_event/build.gradle
index b463565..24e6dff 100644
--- a/examples/ex3_async_event/build.gradle
+++ b/examples/ex3_async_event/build.gradle
@@ -6,7 +6,7 @@
     defaultConfig {
         applicationId "com.google.android.mobly.snippet.example3"
         minSdkVersion 15
-        targetSdkVersion 22
+        targetSdkVersion 26
         versionCode 1
         versionName "0.0.1"
     }
diff --git a/examples/ex4_uiautomator/build.gradle b/examples/ex4_uiautomator/build.gradle
index cd160be..9b4bbe6 100644
--- a/examples/ex4_uiautomator/build.gradle
+++ b/examples/ex4_uiautomator/build.gradle
@@ -1,12 +1,13 @@
 apply plugin: 'com.android.application'
 
 android {
-    compileSdkVersion 26
+    // This has to match what the appcompat dep expects.
+    compileSdkVersion 28
 
     defaultConfig {
         applicationId "com.google.android.mobly.snippet.example4"
         minSdkVersion 18
-        targetSdkVersion 22
+        targetSdkVersion 26
         versionCode 1
         versionName "0.0.2"
     }
diff --git a/examples/ex4_uiautomator/src/main/java/com/google/android/mobly/snippet/example4/UiAutomatorSnippet.java b/examples/ex4_uiautomator/src/main/java/com/google/android/mobly/snippet/example4/UiAutomatorSnippet.java
index 288d1bd..9fc01b2 100644
--- a/examples/ex4_uiautomator/src/main/java/com/google/android/mobly/snippet/example4/UiAutomatorSnippet.java
+++ b/examples/ex4_uiautomator/src/main/java/com/google/android/mobly/snippet/example4/UiAutomatorSnippet.java
@@ -20,7 +20,8 @@
 
 import android.content.Context;
 import android.content.Intent;
-import androidx.test.InstrumentationRegistry;
+
+import androidx.test.platform.app.InstrumentationRegistry;
 import androidx.test.uiautomator.By;
 import androidx.test.uiautomator.UiDevice;
 import androidx.test.uiautomator.UiObject2;
@@ -53,7 +54,7 @@
     private final UiDevice mDevice;
 
     public UiAutomatorSnippet() {
-        mContext = InstrumentationRegistry.getContext();
+        mContext = InstrumentationRegistry.getInstrumentation().getContext();
         mDevice = UiDevice.getInstance(InstrumentationRegistry.getInstrumentation());
     }
 
diff --git a/examples/ex5_schedule_rpc/build.gradle b/examples/ex5_schedule_rpc/build.gradle
index c7426d2..372195d 100644
--- a/examples/ex5_schedule_rpc/build.gradle
+++ b/examples/ex5_schedule_rpc/build.gradle
@@ -6,7 +6,7 @@
     defaultConfig {
         applicationId "com.google.android.mobly.snippet.example5"
         minSdkVersion 15
-        targetSdkVersion 22
+        targetSdkVersion 26
         versionCode 1
         versionName "0.0.1"
     }
diff --git a/third_party/sl4a/build.gradle b/third_party/sl4a/build.gradle
index ce65002..be3672f 100644
--- a/third_party/sl4a/build.gradle
+++ b/third_party/sl4a/build.gradle
@@ -24,7 +24,7 @@
 
     defaultConfig {
         minSdkVersion 15
-        targetSdkVersion 22
+        targetSdkVersion 26
         versionCode VERSION_CODE.toInteger()
         versionName VERSION_NAME