[no-op] Revert "Set crosvm as the default VMM for cuttlefish"

Submitting only so that it shows up in the cuttlefish-testing branch
history.

This reverts commit f275d9206ab6b4c634fd80e19b689f6b2899fc35.

Reason for revert: b/132986546

Bug: 132986546
Test: none
Change-Id: I0bfb206bfe06fae3bc3568aee2f616b80750e5ec
Merged-In: I2616a9de2d4fd46795630a9fbb7a181f834166da