Fix refresh rate callback fan-out for choreographer

* AChoreographer receives refresh rates from DisplayManager
already, so there's no need to default-enable them - AChoreographer only
needs to pump an event with the latest refresh rate to wake up looper. This
also ensures that AChoreographer's callbacks are entirely in-sync with
DisplayManager since there's no raciness.
* Instead of re-requesting a config change from SF, instead inject it in
AChoreographer correctly to save on binder.

Bug: 154874011
Bug: 158680912
Bug: 161406626
Test: while [ true ]; do adb shell service call SurfaceFlinger 1035 i32
1; adb shell service call SurfaceFlinger 1035 i32 0; and repeatedly
rotate the home screen with auto-rotate off.

Change-Id: I66abc2e28e60f06987ce3a54be294c94b77524fc
diff --git a/libs/gui/DisplayEventDispatcher.cpp b/libs/gui/DisplayEventDispatcher.cpp
index 51fbb97..2cc7c34 100644
--- a/libs/gui/DisplayEventDispatcher.cpp
+++ b/libs/gui/DisplayEventDispatcher.cpp
@@ -89,12 +89,8 @@
     return OK;
 }
 
-void DisplayEventDispatcher::requestLatestConfig() {
-    status_t status = mReceiver.requestLatestConfig();
-    if (status) {
-        ALOGW("Failed enable config events, status=%d", status);
-        return;
-    }
+void DisplayEventDispatcher::injectEvent(const DisplayEventReceiver::Event& event) {
+    mReceiver.sendEvents(&event, 1);
 }
 
 int DisplayEventDispatcher::getFd() const {
@@ -156,6 +152,9 @@
                     dispatchConfigChanged(ev.header.timestamp, ev.header.displayId,
                                           ev.config.configId, ev.config.vsyncPeriod);
                     break;
+                case DisplayEventReceiver::DISPLAY_EVENT_NULL:
+                    dispatchNullEvent(ev.header.timestamp, ev.header.displayId);
+                    break;
                 default:
                     ALOGW("dispatcher %p ~ ignoring unknown event type %#x", this, ev.header.type);
                     break;
@@ -167,4 +166,5 @@
     }
     return gotVsync;
 }
+
 } // namespace android