Always flush renderstate in DeferredLayerUpdater::apply

Bug: 34206215
Test: hwui unit tests passing, manual test of TextureView video playback

Always flush renderstate to the GlLayer's texture, regardless of
whether updateTexImage has ever been called.

Change-Id: I3974dce9d90633a0299e6bc4259b76c622717c90
diff --git a/libs/hwui/tests/unit/DeferredLayerUpdaterTests.cpp b/libs/hwui/tests/unit/DeferredLayerUpdaterTests.cpp
index 1ef9dba..87d897e 100644
--- a/libs/hwui/tests/unit/DeferredLayerUpdaterTests.cpp
+++ b/libs/hwui/tests/unit/DeferredLayerUpdaterTests.cpp
@@ -44,7 +44,12 @@
     // push the deferred updates to the layer
     Matrix4 scaledMatrix;
     scaledMatrix.loadScale(0.5, 0.5, 0.0);
-    layerUpdater->updateLayer(true, GL_TEXTURE_EXTERNAL_OES, scaledMatrix.data);
+    layerUpdater->updateLayer(true, scaledMatrix.data);
+    if (layerUpdater->backingLayer()->getApi() == Layer::Api::OpenGL) {
+        GlLayer* glLayer = static_cast<GlLayer*>(layerUpdater->backingLayer());
+        glLayer->setRenderTarget(GL_TEXTURE_EXTERNAL_OES);
+    }
+
 
     // the backing layer should now have all the properties applied.
     if (layerUpdater->backingLayer()->getApi() == Layer::Api::OpenGL) {