Remove duplicated database init function
requested to merge feature/multi_region_support_remove_get_test_db_func into feature/multi_region_support_multiple_platforms
Related tasks
Context
The gorm package contains database related util functions. One such function is GetDBFromEnvVars, which as the name suggests is in charge of establishing a connection to the testing database using environment variable configuration. There is another function right next to it called GetTestDBFromEnvVars which is an exact copy.
Change
Since both GetDBFromEnvVars and GetTestDBFromEnvVars do the same thing, and the functions connect to the test database, GetDBFromEnvVars has been removed in favor of GetTestDBFromEnvVars. All calls to GetDBFromEnvVars have been replaced with calls to GetTestDBFromEnvVars.