Gallery2: Bump minsdk and targetsdk version

Change-Id: I8d7a948286e961d1c2f1beb2a8c199fb1b80b4d2
diff --git a/AndroidManifest.xml b/AndroidManifest.xml
index 6e48bd8..c9a219f 100755
--- a/AndroidManifest.xml
+++ b/AndroidManifest.xml
@@ -24,7 +24,7 @@
 
     <original-package android:name="com.android.gallery3d" />
 
-    <uses-sdk android:minSdkVersion="21" android:targetSdkVersion="28"/>
+    <uses-sdk android:minSdkVersion="23" android:targetSdkVersion="28"/>
 
     <permission android:name="com.android.gallery3d.permission.GALLERY_PROVIDER"
                 android:protectionLevel="signatureOrSystem" />