Allow the use of Cleartext traffic in hostside WebView CTS app.

The WebViewHostSideStartupTest#testCookieManager is currently failing
because it uses cleartext. This CL makes sure cleartext is allowed in
the test app used for WebView CTS hostside tests.

Bug: 77282922
Test: 'cts-tradefed run cts-dev -m CtsHostsideWebViewTests'
Change-Id: I2556abe57804b9eea8fbadd9c5627271edf42b91
1 file changed