Enable resizable activity in AndroidManifest

Added android:resizeableActivity="true" to the application tag in AndroidManifest.xml to support multi-window mode on compatible devices.

Author: AAChartModel

sample/src/main/AndroidManifest.xml

@@ -10,6 +10,7 @@
             android:roundIcon="@mipmap/ic_launcher_round"
             android:supportsRtl="true"
             android:theme="@style/AppTheme"
+            android:resizeableActivity="true"
             tools:ignore="AllowBackup">
         <activity android:name=".basiccontent.MainActivity">
             <intent-filter>