Don't assume resolved classses are filled in for ResolvedFieldAccessTest

The assumption that the dex cache type for class of the field is
resolved is not correct since FindClass does not fill in the
resolved type array. This resulted in crashes if dex_access_to ==
nullptr.

Also implemented for ResolvedMethodAccessTest

Bug: 31277064

Test: Launch ZeroTouch with profile guided compilation.

Change-Id: I40cfb15f3ae4fbfe941fd01ea46211bd86b6e6f7