Add uses-sdk to reduce red squigglies

Change-Id: I70257d7c643b904d8d5a4c462f00267dc0711cd4
diff --git a/packages/SettingsLib/AndroidManifest.xml b/packages/SettingsLib/AndroidManifest.xml
index eacafd5..3873593 100644
--- a/packages/SettingsLib/AndroidManifest.xml
+++ b/packages/SettingsLib/AndroidManifest.xml
@@ -16,5 +16,9 @@
 -->
 
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
-        package="com.android.settingslib">
+    package="com.android.settingslib">
+
+    <uses-sdk
+        android:minSdkVersion="21" />
+
 </manifest>