Change name of the WebView

[redphx]

Is your feature request related to a problem? Please describe.
The current WebView's name is Android System WebView. When installing the WebView it's not really clear that this WebView is from Thorium.

Describe the solution you'd like, including relevant patches or source
Rename Android System WebView to Thorium WebView.
Thanks.

[fathonix]

+1, also change the package id to something other than com.android.webview (such as rocks.thorium.webview) or provide another build that does so alongside the default id one, so Thorium can be selected on the developer options like Bromite. (dup of #54 but arm32 is also affected)