Break dependency between cronet_common_impl and base_java

cronet_common_impl depended on base:base_java just for the sake of
accessing ContextUtils, this dependency provided cronet_common_impl
access to an application-wide context which is used for HttpFlags.
However, `:cronet_impl_common_java` depending on `//base:base_java` is problematic because `//base:base_java` is only shipped in `:native_impl`, not in `:cronet_impl_common_java`. This means someone using `:cronet_impl_common_java` has to depend on `:native_impl`, which is not acceptable, especially if one considers the user may only be interested in :cronet_fallback_impl.

Bug: 299420950
Change-Id: I26c72bb9142a32ec2855ef1ea393a99592a49156
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6498197
Reviewed-by: Etienne Dechamps <edechamps@google.com>
Auto-Submit: Mohannad Farrag <aymanm@google.com>
Commit-Queue: Mohannad Farrag <aymanm@google.com>
Cr-Commit-Position: refs/heads/main@{#1453878}