Import Android SDK Platform P [4719250]

/google/data/ro/projects/android/fetch_artifact \
    --bid 4719250 \
    --target sdk_phone_armv7-win_sdk \
    sdk-repo-linux-sources-4719250.zip

AndroidVersion.ApiLevel has been modified to appear as 28

Change-Id: I9ec0a12c9251b8449dba0d86b0cfdbcca16b0a7c
diff --git a/android/media/MediaTimestamp.java b/android/media/MediaTimestamp.java
index 938dd14..dd43b4e 100644
--- a/android/media/MediaTimestamp.java
+++ b/android/media/MediaTimestamp.java
@@ -98,4 +98,13 @@
                 && (this.nanoTime == that.nanoTime)
                 && (this.clockRate == that.clockRate);
     }
+
+    @Override
+    public String toString() {
+        return getClass().getName()
+                + "{AnchorMediaTimeUs=" + mediaTimeUs
+                + " AnchorSystemNanoTime=" + nanoTime
+                + " clockRate=" + clockRate
+                + "}";
+    }
 }