Fix captive portal can't show certificate problem

Captive portal overrides two shouldOverrideUrlLoading methods,
but show certificate logic only be implemented in deprecated one.

Bug: 133714666
Test: -build, flash, boot
      -atest FramworksNetTests
      -manual test

Change-Id: Ibdcfb814d9552563416fc30b314916559862c361
1 file changed