Fix issue #17752399: Multiple apps broken by GET_TASKS permission change

Keep around GET_TASKS as a permission available to apps, so apps still
think they have it and don't get all uppity because they don't.

Add a new REAL_GET_TASKS that is the actual permission now.

Plus some temporary compatibility code until everyone can transition
fromn GET_TASKS to REAL_GET_TASKS.

Change-Id: I12c1102eed24844685dcbd2fa3b612811603958f
diff --git a/packages/Shell/AndroidManifest.xml b/packages/Shell/AndroidManifest.xml
index 9f9dc23..7e6afa6 100644
--- a/packages/Shell/AndroidManifest.xml
+++ b/packages/Shell/AndroidManifest.xml
@@ -39,7 +39,7 @@
     <uses-permission android:name="android.permission.BLUETOOTH" />
     <uses-permission android:name="android.permission.EXPAND_STATUS_BAR" />
     <!-- System tool permissions granted to the shell. -->
-    <uses-permission android:name="android.permission.GET_TASKS" />
+    <uses-permission android:name="android.permission.REAL_GET_TASKS" />
     <uses-permission android:name="android.permission.CHANGE_CONFIGURATION" />
     <uses-permission android:name="android.permission.REORDER_TASKS" />
     <uses-permission android:name="android.permission.SET_ANIMATION_SCALE" />