Cherry pick Refactor native library path logic in WebViewFactory DO NOT MERGE

This CL changes the relro creation and loading logic.
Instead of using a hardcoded path, now WebViewFactory queries the
package manager to get the lib path, which will be either
/system/priv-app/webview/lib/ or /data/app/... depending on the
presence of an update apk.

Original BUG:16403706
Original Change-Id: Icceb95da98e69032a19ac2ae8fe72ba1439e50ad

Bug: 16723226
Change-Id: Ia3155f72a735d75a566a8cc4c8c892d43b6cd371