Bump targetSdkVersion to "30"

With this CL, versionCode, targetSdkVersion and minSdkVersion will be
bumped/set as follows:

       versionCode: 28 -> 30
  targetSdkVersion: 28 -> 30
     minSdkVersion: 21

As far as we know, there should be no user-visible behavior change on
supported OS versions.

Fix: 189558760
Test: manually verified that LatinIME still is functional
Change-Id: I4bf7588c62fb77bf78d4afcb665e9bfbbef53966
diff --git a/java/AndroidManifest.xml b/java/AndroidManifest.xml
index 9b14928..ac84c33 100644
--- a/java/AndroidManifest.xml
+++ b/java/AndroidManifest.xml
@@ -17,10 +17,10 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
      coreApp="true"
      package="com.android.inputmethod.latin"
-     android:versionCode="28">
+     android:versionCode="30">
 
     <uses-sdk android:minSdkVersion="21"
-         android:targetSdkVersion="28"/>
+         android:targetSdkVersion="30"/>
 
     <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
     <uses-permission android:name="android.permission.DOWNLOAD_WITHOUT_NOTIFICATION"/>