Close keyboard when entering message detail view

Fixes #2598
Close #2802

//FREEBIE

AndroidManifest.xml

@@ -111,7 +111,7 @@
 
     <activity android:name=".MessageDetailsActivity"
               android:label="Message Details"
-              android:windowSoftInputMode="stateUnchanged"
+              android:windowSoftInputMode="stateHidden"
               android:launchMode="singleTask"
               android:configChanges="touchscreen|keyboard|keyboardHidden|orientation|screenLayout|screenSize"/>