Fix nondeterminism in LMS

When provider properties are set asynchronously, there is a race
condition with getProviderProperties on whether those properties are
immediately visible or not. Fix this, and make mock providers disabled
by default (as CTS tests appear to expect).

Bug: 122898923
Test: Manual + CTS
Change-Id: I731b6b12f13f3dce6d4ccaf7d24abe3712a5f3f2