Fix permissions xml and provider access

ThemePicker need to add its use of permissions and declare the
priv app permission parts in an xml file to be able to start.

ThemePicker also need to declare which other apps it intends to
interact with in queries. This enables the Launcher grid/icon preview.

Test: Manual
Bug: 274634330
Change-Id: I55fb94279abeab15dd16a6cabc0bf086c621fc42
diff --git a/Android.bp b/Android.bp
index 3694ea0..b8dcbe5 100644
--- a/Android.bp
+++ b/Android.bp
@@ -94,6 +94,8 @@
         ":ThemePicker_src_overrides",
     ],
 
+    required: ["android.software.theme_picker.xml"],
+
     use_embedded_native_libs: true,
 
     resource_zips: [":WallpaperPicker2_res", ":ThemePicker_res", ":ThemePicker_res_overrides"],
@@ -108,6 +110,13 @@
     system_ext_specific: true,
 }
 
+prebuilt_etc {
+    name: "android.software.theme_picker.xml",
+    system_ext_specific: true,
+    sub_dir: "permissions",
+    src: "android.software.theme_picker.xml",
+}
+
 //
 // Build app code.
 //