Revert "[sts] security test for invalid font size scales"

This reverts commit 4082124096862b4d0fdd891f9aab2e9ee8e949b7.

Reason for revert: per discussion with Manjae, these tests share the same coverage of existing cts tests such as ag/13170098. We will just add @SecurityTest annotation in that test and make sure that is included in the STS modules.

Change-Id: Ica47b05b28a04a8fa111cd2a3d5dad07b7d81644