Avoid writing the keystore if no changes were made

[rogin]

Allow for using the keystore on a readonly filesystem. Currently, a write to the keystore will always occur. This change limits writes to only when necessary.

I welcome others to test by mounting the keystore as readonly. The keystore should not have the default storepass and keypass that that will trigger a write.

I'm considering a test in DefaultConfigurationControllerTest where the modification time of a keystore is checked before and after the call, but that's a lot of investigation to get it written correctly.

Minor other code cleanup was also included.

Related
Original ticket - nextgenhealthcare/connect#5467
Previous PR by @jonbartels - nextgenhealthcare/connect@development...jonbartels:connect:5467-keytore-avoid-writes
Summary table in #121

[tonygermano]

I haven't tested it yet, but I'm fine with this approach.

I would like to see the deprecation of ResourceUtil.closeResourceQuietly broken out to a different PR. It's not related to this keystore change, and the current state of the PR leaves a lot of references calling the deprecated method. I wonder if in some situations we would do better to change the calls to a try-with-resource block rather than using IOUtils.

Could you also please update the javadoc for the two private methods you changed to indicate the purpose of the return value?