[WV] Make `setContentView` not block on WV startup

Once WV constructor is made to not block on WV startup, calling
`setContentView` (which triggers layout inflation) calls two methods
`setLayoutParams` and `onCheckIsTextEditor` which currently triggers and
waits for WV startup. This was checked locally on an emulator running
Android API level 34.

This CL makes changes so that these methods do not synchronously trigger
and block on startup.

Bug: b:437338203
Change-Id: Iecf414babd44d08bb2f0a674d619e90deff2a799
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6884988
Reviewed-by: Richard (Torne) Coles <torne@chromium.org>
Commit-Queue: Abhijith Nair <abhijithnair@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1510968}