Don't abandon child sessions (1/n)

It will throw if abandon() is called on a child session.

Bug: 211944991
Bug: 67862680
Test: to be added
Change-Id: Ib0ba9f3786dda2d3174f3ea8c65d1061a3fcb586
Merged-In: Ib0ba9f3786dda2d3174f3ea8c65d1061a3fcb586
(cherry picked from commit 8b67e7db79d15ab448ae8f00b40a4a350ab3d537)
(cherry picked from commit c685f8b19adcec0dc49ffaa1e94d7caa4f9d05ba)
Merged-In:Ib0ba9f3786dda2d3174f3ea8c65d1061a3fcb586