Rework platform version to hide codenames.

The public platform version no longer can be a codename, it is
always the most recently released platform.  A new build property
and API provides either the offical version or the current codename
as appropriate.  This will avoid breaking apps that look at the
platform version while development is under a codename.

Bug:  143175463
Test: manual
Change-Id: Ie69ffed9d6af6ba0ce8b7b5830634b9b1599292e
diff --git a/prebuilts/androidtv/sample-inputs/app/src/main/java/com/example/android/sampletvinput/player/TvInputPlayer.java b/prebuilts/androidtv/sample-inputs/app/src/main/java/com/example/android/sampletvinput/player/TvInputPlayer.java
index 30ee412..f54b258 100644
--- a/prebuilts/androidtv/sample-inputs/app/src/main/java/com/example/android/sampletvinput/player/TvInputPlayer.java
+++ b/prebuilts/androidtv/sample-inputs/app/src/main/java/com/example/android/sampletvinput/player/TvInputPlayer.java
@@ -452,7 +452,8 @@
         } catch (PackageManager.NameNotFoundException e) {
             versionName = "?";
         }
-        return "SampleTvInput/" + versionName + " (Linux;Android " + Build.VERSION.RELEASE +
+        return "SampleTvInput/" + versionName + " (Linux;Android "
+                + Build.VERSION.RELEASE_OR_CODENAME +
                 ") " + "ExoPlayerLib/" + ExoPlayerLibraryInfo.VERSION;
     }