Add TestApi for setRefreshRateSwitchingType

This CLs adds a test API to replicted the behaviour of the
MATCH_CONTENT_FRAME_RATE user setting. This is intended to
be used from CTS.

Bug: 157504046
Bug: 171952409
Test: atest MatchContentFrameRateTest
Change-Id: I90d9a0d019cdb908b3b13328a78fe370676ad064
diff --git a/packages/Shell/AndroidManifest.xml b/packages/Shell/AndroidManifest.xml
index 2e3ea24..92b1ca7 100644
--- a/packages/Shell/AndroidManifest.xml
+++ b/packages/Shell/AndroidManifest.xml
@@ -332,6 +332,9 @@
     <!-- Permission needed for CTS test - DisplayTest -->
     <uses-permission android:name="android.permission.OVERRIDE_DISPLAY_MODE_REQUESTS" />
 
+    <!-- Permission needed for CTS test - MatchContentFrameRateTest -->
+    <uses-permission android:name="android.permission.MODIFY_REFRESH_RATE_SWITCHING_TYPE" />
+
     <!-- Permission needed for CTS test - TimeManagerTest -->
     <uses-permission android:name="android.permission.MANAGE_TIME_AND_ZONE_DETECTION" />