incorporate erinn's feebback so android back button interacts with stack!

go/gothings/android/CwtchActivity.go

@@ -15,7 +15,7 @@ type CwtchActivity struct {
 
 	_ func(string) `slot:"updateAndroidNotification"`
 
-	_ func() `signal:"rootHomeButtonHandle,auto""`
+	_ func() `signal:"rootHomeButtonHandle,auto"`
 }
 
 func (c *CwtchActivity) init() {

qml/main.qml

@@ -200,7 +200,13 @@ ApplicationWindow {
         Keys.onPressed: {
             if (event.key == Qt.Key_Back) {
                 event.accepted = true
-                androidCwtchActivity.rootHomeButtonHandle()
+                if (theStack.currentIndex == theStack.emptyPane) {
+                    androidCwtchActivity.rootHomeButtonHandle()
+                } else if (theStack.currentIndex == theStack.userProfilePane || theStack.currentIndex == theStack.groupProfilePane) {
+                    theStack.currentIndex = theStack.messagePane
+                } else {
+                    theStack.currentIndex = theStack.emptyPane
+                }
             }
         }
 	}