Issue 2561 - Installing extensions should not be allowed until official support lands

mobile/android/base/AndroidManifest.xml.in

 #filter substitution
 <?xml version="1.0" encoding="utf-8"?>
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
       package="@ANDROID_PACKAGE_NAME@"
       android:installLocation="auto"
       android:versionCode="@ANDROID_VERSION_CODE@"
       android:versionName="@MOZ_APP_VERSION@"
 #ifdef MOZ_ANDROID_SHARED_ID
       android:sharedUserId="@MOZ_ANDROID_SHARED_ID@"
 #endif
@@ skipping 183 matching lines @@
                 <category android:name="android.intent.category.BROWSABLE" />
                 <data android:scheme="" />
                 <data android:scheme="http" />
                 <data android:scheme="https" />
             </intent-filter>
 
             <intent-filter>
                 <action android:name="android.intent.action.SEARCH" />
             </intent-filter>
 
-                  <!-- For XPI installs from websites and the download manager. -->
-                  <!-- We disable XPI installation here because of https://issues.adblockplus.org/ticket/2561 -->
+            <!-- For XPI installs from websites and the download manager. -->
+            <!-- We disable XPI installation here because of https://issues.adblockplus.org/ticket/2561 -->
             <!-- <intent-filter>
                 <action android:name="android.intent.action.VIEW" />
                 <category android:name="android.intent.category.DEFAULT" />
                 <data android:scheme="file" />
                 <data android:scheme="http" />
                 <data android:scheme="https" />
                 <data android:mimeType="application/x-xpinstall" />
             </intent-filter> -->
 
             <!-- For XPI installs from file: URLs. -->
-                  <!-- We disable XPI installation here because of https://issues.adblockplus.org/ticket/2561 -->
+            <!-- We disable XPI installation here because of https://issues.adblockplus.org/ticket/2561 -->
             <!-- <intent-filter>
                 <action android:name="android.intent.action.VIEW" />
                 <category android:name="android.intent.category.DEFAULT" />
                 <data android:host="" />
                 <data android:scheme="file" />
                 <data android:pathPattern=".*\\.xpi" />
             </intent-filter> -->
 
 #ifdef MOZ_ANDROID_BEAM
             <intent-filter>
@@ skipping 236 matching lines @@
     <permission android:name="@ANDROID_PACKAGE_NAME@.permissions.BROWSER_PROVIDER"
                 android:protectionLevel="signature"/>
 
     <permission android:name="@ANDROID_PACKAGE_NAME@.permissions.PASSWORD_PROVIDER"
                 android:protectionLevel="signature"/>
 
     <permission android:name="@ANDROID_PACKAGE_NAME@.permissions.FORMHISTORY_PROVIDER"
                 android:protectionLevel="signature"/>
 
 </manifest>