Use "try-catch" block instead of "if" block to prevent interruption of new installation

Use "try-catch" block instead of "if" block to prevent interruption of new installation

New installation blocked when checking if the DB exists,
because when select DB, if it fails, it will throw an exception.

So I modify the checking logic to determine if there is an exception
thrown instead of detecting the return value.

Bug: T215566
Change-Id: I6817997434df7adc79fbc1b224b77c0daa8cc11d