Revert "Remove FileManager unit test"

This reverts commit ac73682a3d.

src/qgcunittest/UnitTestList.cc

@@ -52,6 +52,7 @@ UT_REGISTER_TEST(MissionControllerTest)
 UT_REGISTER_TEST(MissionManagerTest)
 UT_REGISTER_TEST(RadioConfigTest)
 UT_REGISTER_TEST(TCPLinkTest)
+UT_REGISTER_TEST(FileManagerTest)
 UT_REGISTER_TEST(ParameterManagerTest)
 UT_REGISTER_TEST(MissionCommandTreeTest)
 UT_REGISTER_TEST(LogDownloadTest)
@@ -69,8 +70,5 @@ UT_REGISTER_TEST(QGCMapPolygonTest)
 // FIXME: Temporarily disabled until this can be stabilized
 //UT_REGISTER_TEST(MainWindowTest)
 
-// Onboard file support has been removed until it can be make to work correctly
-//UT_REGISTER_TEST(FileManagerTest)
-
 // Needs to be update for latest updates
 //UT_REGISTER_TEST(MavlinkLogTest)