WIP: egl: platform_android: prevent deadlock in eglMakeCurrent

eglMakeCurrent would call dri_make_current and then droid_image_get_buffers and then android::BufferQueueProducer::dequeueBuffer which could call eglClientWaitSyncKHR. To avoid dead lock, release the display mutex before calling it and re-access it afterwards. We already have similar logic in droid_window_enqueue_buffer

Signed-off-by: Lepton Wu lepton@chromium.org