google_pixel: ThemePickerGoogle: Import pixel themes stub package

Change-Id: I1e7c2e4f04c28db7c181892978ff5429fcc74437

ThemePickerGoogle/Android.bp

@@ -111,3 +111,13 @@ android_app {
         "PixelThemesStub",
     ],
 }
+
+android_app_import {
+    name: "PixelThemesStub",
+    apk: "PixelThemesStub.apk",
+    presigned: true,
+    product_specific: true,
+    dex_preopt: {
+        enabled: false,
+    },
+}