Fix memory leaks in libcompositionengine_test

LayerFE inherits from RefBase and therefore must be held by an sp<>.
Creating a RefBase object without an sp<> causes a memory leak.

Test: adb shell /data/nativetest64/libcompositionengine_test/libcompositionengine_test
Bug: 181807839
Change-Id: I937870a036118ef567536d31d847fa691f42f2c2
2 files changed