Remove obsolete build options from .bazelrc (#1119)

This commit removes the following bazel options that were originally
added [1] to support bzlmod for Android (#1002).

 - experimental_enable_android_migration_apis
 - experimental_google_legacy_api

As far as we can see with Bazel 7.4.0, building Mozc with Bazel just
succeeds without the above two options in all the supported platforms.

Closes #1117.

 [1]: 699c2ce

PiperOrigin-RevId: 694063797

src/.bazelrc

@@ -65,6 +65,4 @@ build:windows_env --noincompatible_enable_cc_toolchain_resolution
 # Android specific options
 build:android_env --copt "-DOS_ANDROID"
 build:android_env --build_tag_filters=-noandroid
-build:android_env --experimental_enable_android_migration_apis
-build:android_env --experimental_google_legacy_api
 test:android_env  --test_tag_filters=-noandroid