Add switchToRbacRole=True to test instance actions in compute.

As the title says, switchToRbacRole=True is not performed in
either of the 2 tests. Also, the test file should be renamed
from test_instance_actions => test_instance_actions_rbac.

This patch resolves both issues.

Change-Id: I2a21c63af491466c94a1a94bb69e48eb9d31ab16
Closes-Bug: #1672445
1 file changed