Add minSdkVersion in AndroidManifest for SpaLib & Gallery.

Bug: 244122804
Test: manual - build gallery
Change-Id: Id8c54243a6da468324594df062918e0917e216ac
diff --git a/packages/SettingsLib/Spa/gallery/AndroidManifest.xml b/packages/SettingsLib/Spa/gallery/AndroidManifest.xml
index 0a4972f..2ed8bca 100644
--- a/packages/SettingsLib/Spa/gallery/AndroidManifest.xml
+++ b/packages/SettingsLib/Spa/gallery/AndroidManifest.xml
@@ -17,6 +17,8 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     package="com.android.settingslib.spa.gallery">
 
+    <uses-sdk android:minSdkVersion="21"/>
+
     <application
         android:name=".GalleryApplication"
         android:icon="@mipmap/ic_launcher"