Revert "Default shell_starting_surface to true to match platform behavior."

This reverts commit 6acba271098712d64d3977569f0dc1349a231e58.

Reason for revert: https://b.corp.google.com/issues/185818929#comment4

Change-Id: I30875c1f81808b92f529bd11c916fea05b93fd4d
1 file changed