Delay idleModeTimer until splash screen has closed

If the UI loads before the splash screen has finished, the
idleModeTimer starts too early, resulting in an odd visual effect
where the nav bar disappears and reappears when tapped.

pages/PageManager.qml

@@ -30,7 +30,8 @@ QtObject {
 			|| root.interactivity === VenusOS.PageManager_InteractionMode_Idle
 
 	property Timer idleModeTimer: Timer {
-		running: root.currentPage !== null && root.currentPage !== undefined
+		running: !Global.splashScreenVisible
+			&& root.currentPage !== null && root.currentPage !== undefined
 			&& root.currentPage.fullScreenWhenIdle
 			&& root.interactivity === VenusOS.PageManager_InteractionMode_Interactive
 			&& BackendConnection.applicationVisible