add app launcher icon

android/app/src/main/AndroidManifest.xml

@@ -4,9 +4,9 @@
 
     <application
         android:allowBackup="true"
-        android:icon="@mipmap/ic_launcher"
+        android:icon="@mipmap/chatman_launcher"
         android:label="@string/app_name"
-        android:roundIcon="@mipmap/ic_launcher_round"
+        android:roundIcon="@mipmap/chatman_launcher_round"
         android:supportsRtl="true"
         android:theme="@style/AppTheme">
         <activity

android/app/src/main/res/values/strings.xml

 <resources>
-    <string name="app_name">chatman</string>
+    <string name="app_name">ChatMan</string>
     <string name="navigation_drawer_open">Open navigation drawer</string>
     <string name="navigation_drawer_close">Close navigation drawer</string>
     <string name="nav_header_title">Android Studio</string>