Avoid repeating grpc version in Android documentation

This removes some steps from the release process. These two locations
aren't special enough in way that deserves manually changing the version
each release.

RELEASING.md

@@ -104,8 +104,6 @@ Tagging the Release
    # Bump documented gRPC versions.
    # Also update protoc version to match protobuf version in gradle/libs.versions.toml.
    $ ${EDITOR:-nano -w} README.md
-   $ ${EDITOR:-nano -w} documentation/android-channel-builder.md
-   $ ${EDITOR:-nano -w} cronet/README.md
    
    $ git commit -a -m "Update README etc to reference $MAJOR.$MINOR.$PATCH"
    ```

cronet/README.md

@@ -22,13 +22,9 @@ See the example app at https://github.com/GoogleChrome/cronet-sample/blob/master
 
 ## Example usage:
 
-In your app module's `build.gradle` file, include a dependency on both `grpc-cronet` and the 
-Google Play Services Client Library for Cronet
-
-```
-implementation 'io.grpc:grpc-cronet:1.54.0'
-implementation 'com.google.android.gms:play-services-cronet:16.0.0'
-```
+In your app module's `build.gradle` file, include a dependency on both
+`io.grpc:grpc-cronet` and the Google Play Services Client Library for Cronet,
+`com.google.android.gms:play-services-cronet`.
 
 In cases where Cronet cannot be loaded from Google Play services, there is a less performant 
 implementation of Cronet's API that can be used. Depend on `org.chromium.net:cronet-fallback` 

documentation/android-channel-builder.md

@@ -32,13 +32,8 @@ connection management on Android devices.*
 
 ## Example usage:
 
-In your `build.gradle` file, include a dependency on both `grpc-android` and
-`grpc-okhttp`:
-
-```
-implementation 'io.grpc:grpc-android:1.54.0'
-implementation 'io.grpc:grpc-okhttp:1.54.0'
-```
+In your `build.gradle` file, include a dependency on both `io.grpc:grpc-android` and
+`io.grpc:grpc-okhttp`.
 
 You also need permission to access the device's network state in your
 `AndroidManifest.xml`: