LPS-52030 "clearAll" here means remove all entries in caches but not cache itself, so we need also keep _portalCaches here.
LPS-52030 It is OK to not define default cache, add null check to avoid NPE.
LPS-50230 Configuration for portal cache should also be updated after reconfiguring.
LPS-52030 Inner ehcache instance should be updated after reconfiguring.
LPS-52030 Fix unit tests.
LPS-52030 SF