GpuStats: rename an api and add unit tests

1. insertStats is renamed to insertDriverStats
2. dump all before clear all
3. unit tests have been added

Bug: 141392969
Test: atest gpuservice_unittest
Change-Id: Ifa936bbfd071166a72d1990baf49be0e5ec17fa4
diff --git a/services/gpuservice/tests/unittests/Android.bp b/services/gpuservice/tests/unittests/Android.bp
new file mode 100644
index 0000000..fee5bd4
--- /dev/null
+++ b/services/gpuservice/tests/unittests/Android.bp
@@ -0,0 +1,34 @@
+// Copyright 2020 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+cc_test {
+    name: "gpuservice_unittest",
+    test_suites: ["device-tests"],
+    sanitize: {
+        address: true,
+    },
+    srcs: [
+        "GpuStatsTest.cpp",
+    ],
+    shared_libs: [
+        "libcutils",
+        "libgfxstats",
+        "libgraphicsenv",
+        "liblog",
+        "libutils",
+    ],
+    static_libs: [
+        "libgmock",
+    ],
+}