Re-add items to .Main activity alias.

Recent changes to how MAIN intent are handled (crrev.com/c/667936 and
crrev.com/c/700803) left .Main activity alias without two items it
previously had:

1. "android.app.shortcuts" metadata. This caused tab shortcuts to
disappear (see the bug), because the metadata should be in the activity
that handles MAIN/LAUNCHER intents.

2. "supports_vr" block. The block adds VR-related categories so that
activity is recognized as supporting VR.

This CL moves "android.app.shortcuts" metadata back to .Main, and adds
the VR block.

Bug: 772079
Change-Id: I6cade1a7a35d4439d6ecb951760e57e1f73d58f5
Reviewed-on: https://chromium-review.googlesource.com/703214
Reviewed-by: Theresa <twellington@chromium.org>
Reviewed-by: Ted Choc <tedchoc@chromium.org>
Commit-Queue: Dmitry Skiba <dskiba@chromium.org>
Cr-Commit-Position: refs/heads/master@{#507102}

chrome/android/java/AndroidManifest.xml

@@ -260,8 +260,6 @@ by a child template that "extends" this file.
             </intent-filter>
             <meta-data android:name="android.app.searchable"
                 android:resource="@xml/searchable" />
-            <meta-data android:name="android.app.shortcuts"
-                android:resource="@xml/launchershortcuts" />
 
             {{ self.supports_vr() }}
         </activity-alias>
@@ -411,6 +409,9 @@ by a child template that "extends" this file.
                 <category android:name="android.intent.category.MULTIWINDOW_LAUNCHER" />
                 {% endif %}
             </intent-filter>
+            <meta-data android:name="android.app.shortcuts"
+                android:resource="@xml/launchershortcuts" />
+            {{ self.supports_vr() }}
         </activity-alias>
         <activity android:name="org.chromium.chrome.browser.ChromeTabbedActivity2"
             android:theme="@style/TabbedModeTheme"