Camera: fix wrong signalStreamFlush call

Sometimes the waitUntilIdle call will finish without RequestThread
sending the signalStreamFlush call down to HAL.
Reset the flag when the wait finishes to avoid a wrong call fired
later when the request thread goes to paused.

Test: CTS on Pixel 3, partner testing
Bug: 162062652
Change-Id: I7c6674860a688f0bc42d4083793514b546cbd65d
diff --git a/services/camera/libcameraservice/device3/Camera3Device.cpp b/services/camera/libcameraservice/device3/Camera3Device.cpp
index 4a509aa..7b3dfb4 100644
--- a/services/camera/libcameraservice/device3/Camera3Device.cpp
+++ b/services/camera/libcameraservice/device3/Camera3Device.cpp
@@ -1833,10 +1833,12 @@
 
     mStatusWaiters++;
 
+    bool signalPipelineDrain = false;
     if (!active && mUseHalBufManager) {
         auto streamIds = mOutputStreams.getStreamIds();
         if (mStatus == STATUS_ACTIVE) {
             mRequestThread->signalPipelineDrain(streamIds);
+            signalPipelineDrain = true;
         }
         mRequestBufferSM.onWaitUntilIdle();
     }
@@ -1866,6 +1868,10 @@
         }
     } while (!stateSeen);
 
+    if (signalPipelineDrain) {
+        mRequestThread->resetPipelineDrain();
+    }
+
     mStatusWaiters--;
 
     return res;
@@ -4785,6 +4791,12 @@
     mStreamIdsToBeDrained = streamIds;
 }
 
+void Camera3Device::RequestThread::resetPipelineDrain() {
+    Mutex::Autolock pl(mPauseLock);
+    mNotifyPipelineDrain = false;
+    mStreamIdsToBeDrained.clear();
+}
+
 void Camera3Device::RequestThread::clearPreviousRequest() {
     Mutex::Autolock l(mRequestLock);
     mPrevRequest.clear();
diff --git a/services/camera/libcameraservice/device3/Camera3Device.h b/services/camera/libcameraservice/device3/Camera3Device.h
index 408f1f9..4c5f484 100644
--- a/services/camera/libcameraservice/device3/Camera3Device.h
+++ b/services/camera/libcameraservice/device3/Camera3Device.h
@@ -832,6 +832,7 @@
         }
 
         void signalPipelineDrain(const std::vector<int>& streamIds);
+        void resetPipelineDrain();
 
         status_t switchToOffline(
                 const std::vector<int32_t>& streamsToKeep,