Implement Report persistency

Now Report properties are stored in non-volatile memory. It allows
to restore Report after system restart. Persistency of a report is
controlled by Persistency property in Report interface.

Tested:
 - Passed unit tests
 - Verified that report is stored in /var/lib/telemetry dir
 - Verified that report is restored from storage after telemetry
   service start

Signed-off-by: Wludzik, Jozef <jozef.wludzik@intel.com>
Change-Id: Iccfe21603eecffc4e174a4403f699b03de320db9
diff --git a/tests/meson.build b/tests/meson.build
index 73846f6..2bf9dfb 100644
--- a/tests/meson.build
+++ b/tests/meson.build
@@ -40,6 +40,7 @@
             'src/test_report_manager.cpp',
             'src/test_sensor.cpp',
             'src/test_sensor_cache.cpp',
+            'src/test_transform.cpp',
             'src/test_unique_call.cpp',
             'src/utils/generate_unique_mock_id.cpp',
         ],