Do not set buttons on touch events

BUTTON_PRIMARY must not be set for touch events:

> This button constant is not set in response to simple touches with a
> finger or stylus tip. The user must actually push a button.

<https://developer.android.com/reference/android/view/MotionEvent#BUTTON_PRIMARY>

Fixes #2169 <https://github.com/Genymobile/scrcpy/issues/2169>

server/src/main/java/com/genymobile/scrcpy/Controller.java

@@ -208,6 +208,10 @@ public class Controller {
         // Right-click and middle-click only work if the source is a mouse
         boolean nonPrimaryButtonPressed = (buttons & ~MotionEvent.BUTTON_PRIMARY) != 0;
         int source = nonPrimaryButtonPressed ? InputDevice.SOURCE_MOUSE : InputDevice.SOURCE_TOUCHSCREEN;
+        if (source != InputDevice.SOURCE_MOUSE) {
+            // Buttons must not be set for touch events
+            buttons = 0;
+        }
 
         MotionEvent event = MotionEvent
                 .obtain(lastTouchDown, now, action, pointerCount, pointerProperties, pointerCoords, 0, buttons, 1f, 1f, DEFAULT_DEVICE_ID, 0, source,