Reland "Modify user agent CTS test to match new webview user agent string."

The original CL was reverted in L-cts-dev because L-devices can have
older versions of webview without the new user agent string. That revert
should not have propagated to mnc-dev.

This reverts commit 39eabb9c7d68e559f4ce3f341070159f23bad037.
1 file changed