Start inserting meta-data version tags per library.

Originally, we inserted one tag for all support library, however
we have libraries (e.g. Lifecycles) that have different versioning
and to support that use case we need to insert a version number per
library.

Test: ./gradlew assembleDebug
Change-Id: Iea71416026e64781ddc249be94ef5242208c1701
diff --git a/customtabs/AndroidManifest.xml b/customtabs/AndroidManifest.xml
index 4069dae..6a25c8a 100644
--- a/customtabs/AndroidManifest.xml
+++ b/customtabs/AndroidManifest.xml
@@ -17,6 +17,7 @@
           package="android.support.customtabs">
     <uses-sdk android:minSdkVersion="15"/>
     <application>
-        <meta-data android:name="android.support.VERSION" android:value="${support-version}" />
+        <meta-data android:name="android.support.customtabs.VERSION"
+                   android:value="${support-version}" />
     </application>
 </manifest>