Allow overriding WebView/Trichrome app labels.

Add an application_label variable to the WebView and TrichromeLibrary
manifests so that the default application label can be overridden with a
jinja variable. This will be used to differentiate channel builds.

Bug: 954668
Change-Id: I9a18c7c9ae393f374713471a9103a812f2c0a104
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1579660Reviewed-by: Andrew Grieve <agrieve@chromium.org>
Commit-Queue: Richard Coles <torne@chromium.org>
Cr-Commit-Position: refs/heads/master@{#653615}

android_webview/apk/java/AndroidManifest.xml

@@ -21,7 +21,7 @@
     <uses-permission android:name="android.permission.INTERNET" />
     <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
 
-    <application android:label="Android System WebView"
+    <application android:label="{{ application_label|default('Android System WebView') }}"
                  android:icon="@{{manifest_package|default('com.android.webview')}}:drawable/icon_webview"
                  android:name="{{ application_name|default('com.android.webview.chromium.WebViewApplication') }}"
                  android:multiArch="true"

chrome/android/java/AndroidManifest_trichrome_library.xml

@@ -19,7 +19,7 @@ Note: This is a jinja2 template, processed at build time into the final manifest
 
     <!-- TODO(torne): we should specify an icon, roundIcon, and label from resources. -->
     <application
-        android:label="Trichrome Library"
+        android:label="{{ application_label|default('Trichrome Library') }}"
         android:icon="@drawable/icon_webview"
         android:multiArch="true"
         android:extractNativeLibs="false">