Create APIs to interact with DynamicPowerSaver

This creates the PowerManager APIs that allow apps with the
appropriate permissions to interact with Dynamic Power Saver.

Bug: 111450127
Test: WIP
Change-Id: I5b9483fa0fba81a4ade622b1f3dbaec580b68a67
diff --git a/data/etc/privapp-permissions-platform.xml b/data/etc/privapp-permissions-platform.xml
index a1fbe0a..c7945bd02 100644
--- a/data/etc/privapp-permissions-platform.xml
+++ b/data/etc/privapp-permissions-platform.xml
@@ -324,6 +324,7 @@
         <permission name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"/>
         <permission name="android.permission.MOVE_PACKAGE"/>
         <permission name="android.permission.PACKAGE_USAGE_STATS" />
+        <permission name="android.permission.POWER_SAVER" />
         <permission name="android.permission.READ_FRAME_BUFFER"/>
         <permission name="android.permission.READ_LOWPAN_CREDENTIAL"/>
         <permission name="android.permission.READ_PRIVILEGED_PHONE_STATE"/>