Fix uninitialized repeat count in key events

A new "repeat" field has been added by
3c1ed5d86c, but it was not initialized in
every code path.

As a consequence, keycodes generated by shortcuts were sent with an
undetermined value, breaking some shortcuts (especially HOME) randomly.

Fixes #1643 <https://github.com/Genymobile/scrcpy/issues/1643>

app/src/input_manager.c

@@ -80,6 +80,7 @@ send_keycode(struct controller *controller, enum android_keycode keycode,
     msg.type = CONTROL_MSG_TYPE_INJECT_KEYCODE;
     msg.inject_keycode.keycode = keycode;
     msg.inject_keycode.metastate = 0;
+    msg.inject_keycode.repeat = 0;
 
     if (actions & ACTION_DOWN) {
         msg.inject_keycode.action = AKEY_EVENT_ACTION_DOWN;