docs: Request coarse location with b.g. location

When requesting background location access (for "all-the-time" access
to device location), it's possible to request *either* coarse or fine
location access along with background location access. Updated the
docs to mention this important point.

Test: make ds-docs -j32

Bug: 133248358
Change-Id: Ia10e493ecb33b6e971b53d3ff348a495417d9b38
diff --git a/core/res/AndroidManifest.xml b/core/res/AndroidManifest.xml
index 142e2a4..1c1225b 100644
--- a/core/res/AndroidManifest.xml
+++ b/core/res/AndroidManifest.xml
@@ -904,9 +904,9 @@
         android:backgroundPermission="android.permission.ACCESS_BACKGROUND_LOCATION"
         android:protectionLevel="dangerous|instant" />
 
-    <!-- Allows an app to access location in the background.  If you
-         are requesting this, you should also request {@link #ACCESS_FINE_LOCATION}.
-         Requesting this by itself is not sufficient to give you
+    <!-- Allows an app to access location in the background. If you're requesting this permission,
+         you must also request either {@link #ACCESS_COARSE_LOCATION} or
+         {@link #ACCESS_FINE_LOCATION}. Requesting this permission by itself doesn't give you
          location access.
          <p>Protection level: dangerous
     -->