Android: VncCanvasActivity: fix cuttext sending

mClipboardManager.hasText() would return false on non-antique
Android versions. onWindowFocusChange() is the right place, see
https://developer.android.com/reference/android/content/ClipboardManager#hasPrimaryClip()

re #252

android/app/src/main/java/com/coboltforge/dontmind/multivnc/ui/VncCanvasActivity.java

@@ -487,17 +487,6 @@ protected void onResume() {
 		super.onResume();
 		// needed for the GLSurfaceView
 		vncCanvas.onResume();
-
-		// get Android clipboard contents
-		if (mClipboardManager.hasText()) {
-			try {
-				vncCanvas.vncConn.sendCutText(mClipboardManager.getText().toString());
-			}
-			catch(NullPointerException e) {
-				//unused
-			}
-		}
-
 	}
 
 	/**
@@ -840,6 +829,16 @@ public void onWindowFocusChanged(boolean hasFocus) {
 		super.onWindowFocusChanged(hasFocus);
 		if (hasFocus) {
 			hideSystemUI();
+
+			// get Android clipboard contents
+			if (mClipboardManager.hasText()) {
+				try {
+					vncCanvas.vncConn.sendCutText(mClipboardManager.getText().toString());
+				}
+				catch(NullPointerException e) {
+					//unused
+				}
+			}
 		}
 	}