[TECHNICAL REQUEST] LPS-51101 Fix tests

Hi Julio,

This is a continuation of https://github.com/brianchandotcom/liferay-portal/pull/22226

You reviewed this pull already, but some tests failed. I fixed the tests and I did not touch the code which was reviewed by you, so I think, it is enough to take a look at the last two commits:

LPS-51101 unit test - set back default locale
LPS-51101 unit test - set default language in PortalImplAlternateURLT… 

The root cause (why the tests failed) was that the tests rely on that the portal's default language is US, which was set to German by my new test methods in LanguageImplTest.

I set back the default language in LanguageImplTest and I fixed the other tests to not rely "blindly" on the default language.

Thank you in advance
Péter Borkuti