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/AndroidTest.xml b/services/gpuservice/tests/unittests/AndroidTest.xml
new file mode 100644
index 0000000..66f51c7
--- /dev/null
+++ b/services/gpuservice/tests/unittests/AndroidTest.xml
@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- 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.
+-->
+<configuration description="Config for gpuservice_unittest">
+    <target_preparer class="com.android.tradefed.targetprep.PushFilePreparer">
+        <option name="cleanup" value="true" />
+        <option name="push" value="gpuservice_unittest->/data/local/tmp/gpuservice_unittest" />
+    </target_preparer>
+    <option name="test-suite-tag" value="apct" />
+    <test class="com.android.tradefed.testtype.GTest" >
+        <option name="native-test-device-path" value="/data/local/tmp" />
+        <option name="module-name" value="gpuservice_unittest" />
+    </test>
+</configuration>