Explicit API for allocating disk space.

Now that we're giving apps better guidance around how much cached
disk space they can use, we also need to provide a way to help clear
some of those cached files.  The final logic is coming in a future
CL, but it will be designed to prevent abuse.

Test: newly added CTS tests
Bug: 34690590
Change-Id: I1e46ade0cdabbc33162fc7bfa76abec711992f92
diff --git a/core/res/AndroidManifest.xml b/core/res/AndroidManifest.xml
index 5b5e61e..cd02fbb 100644
--- a/core/res/AndroidManifest.xml
+++ b/core/res/AndroidManifest.xml
@@ -1650,6 +1650,12 @@
     <permission android:name="android.permission.CACHE_CONTENT"
         android:protectionLevel="signature" />
 
+    <!-- Allows an application to aggressively allocate disk space.
+         <p>Not for use by third-party applications.
+    -->
+    <permission android:name="android.permission.ALLOCATE_AGGRESSIVE"
+        android:protectionLevel="signature|privileged" />
+
     <!-- ================================== -->
     <!-- Permissions for screenlock         -->
     <!-- ================================== -->