Rewrites CTS test for key/value backup

Previous implementation used logcat as means of communication between
the test app on the device and the host side of the test. Due to the
nature of logcat that proved to be unreliable and flaky.

New implementation uses device-side test routines to save, read and
verify shared preferences and files. The host side is used to drive the
test flow, install and uninstall the test app, run backup and restore commands.

Test: cts-tradefed run cts -m CtsBackupHostTestCases -t android.cts.backup.KeyValueBackupRestoreHostSideTest
Bug: 38331563
Change-Id: I0d3082c7b0088965f9d018aeb35eae6244f80018
diff --git a/hostsidetests/backup/SharedPreferencesRestoreApp/Android.mk b/hostsidetests/backup/SharedPreferencesRestoreApp/Android.mk
new file mode 100644
index 0000000..bd6929a
--- /dev/null
+++ b/hostsidetests/backup/SharedPreferencesRestoreApp/Android.mk
@@ -0,0 +1,39 @@
+# Copyright (C) 2017 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.
+
+LOCAL_PATH:= $(call my-dir)
+
+include $(CLEAR_VARS)
+
+# Don't include this package in any target
+LOCAL_MODULE_TAGS := tests
+# When built, explicitly put it in the data partition.
+LOCAL_MODULE_PATH := $(TARGET_OUT_DATA_APPS)
+
+LOCAL_DEX_PREOPT := false
+
+LOCAL_PROGUARD_ENABLED := disabled
+
+LOCAL_STATIC_JAVA_LIBRARIES := android-support-test
+
+LOCAL_SRC_FILES := $(call all-java-files-under, src)
+
+# tag this module as a cts test artifact
+LOCAL_COMPATIBILITY_SUITE := cts
+
+LOCAL_PACKAGE_NAME := CtsSharedPreferencesRestoreApp
+
+LOCAL_SDK_VERSION := current
+
+include $(BUILD_PACKAGE)