Fixed selfManaged call issue

The self-managed call will set active directly. If there is an active
call, we should hold or disconnect it based on the holdability.

Test: runtest -x CallsManagerTest.java
Bug: 76016794
Merged-In: I053a50997facd108053380eac115464c7fa7e011
Change-Id: I053a50997facd108053380eac115464c7fa7e011
(cherry picked from commit 8229bc96)