Grant READ_DREAM_STATE & WRITE_DREAM_STATE permissions to shell

This is required for ambient display tests.

NOTE: This CL is manually cherry-picked from aosp/1215115 due to
merge conflict.

Bug: 147874708
Test: Run newly added ambient display tests.
Change-Id: I61c28e15c4e5c3d0ffee4137ecb86e33f7e8f64d
diff --git a/packages/Shell/AndroidManifest.xml b/packages/Shell/AndroidManifest.xml
index fb9bc52..f0dc606 100644
--- a/packages/Shell/AndroidManifest.xml
+++ b/packages/Shell/AndroidManifest.xml
@@ -239,6 +239,10 @@
     <!-- Allows setting brightness from the shell -->
     <uses-permission android:name="android.permission.CONTROL_DISPLAY_BRIGHTNESS"/>
 
+    <!-- Permissions required to test ambient display. -->
+    <uses-permission android:name="android.permission.READ_DREAM_STATE"/>
+    <uses-permission android:name="android.permission.WRITE_DREAM_STATE"/>
+
     <application android:label="@string/app_label"
                 android:theme="@android:style/Theme.DeviceDefault.DayNight"
                 android:defaultToDeviceProtectedStorage="true"