update webviewbootstrap apex

Remove overriding field min_sdk_version, which is already defined in
v-launched-apex-module.

min_sdk_version was overridden when V was not finalized. Since V is finalized now, there override should not be required anymore.

Flag: EXEMPT removing overriding property is not flagged
Bug: 361092707
Test: m com.android.webview.bootstrap
Change-Id: I0990414a9ecc26dbb6daac6d2a09cce27a3b1324