Fixed flaky RenderScript VTS Test

Added missing synchronization before context destroy

Bug: 38385848
Test: make vts, does not fail with multiple tests
Change-Id: Ib0d038969e9a1d6f5ea555ccb60fed55b69e05dc
diff --git a/renderscript/1.0/vts/functional/VtsHalRenderscriptV1_0TargetTest.cpp b/renderscript/1.0/vts/functional/VtsHalRenderscriptV1_0TargetTest.cpp
index f505d01..2670b8d 100644
--- a/renderscript/1.0/vts/functional/VtsHalRenderscriptV1_0TargetTest.cpp
+++ b/renderscript/1.0/vts/functional/VtsHalRenderscriptV1_0TargetTest.cpp
@@ -28,6 +28,7 @@
 }
 
 void RenderscriptHidlTest::TearDown() {
+    context->contextFinish();
     context->contextDestroy();
 }