Annotate RemoteConfig with Nullity annotations

[xenoterracide]

Description

simply add @NonNull/@Nullable to the RemoteConfig class

Motivation

I'm getting an unsafe null, my headBranch method parameter @nonnull

      .map(s -> s.map(r -> { // r is RemoteConfig
        var name = r.getName();
        return new RemoteImpl(name, this.headBranch(name));
      }))

/home/xeno/IdeaProjects/gradle-semver/module/semver/src/main/java/com/xenoterracide/gradle/semver/internal/GitMetadataImpl.java:181: error: [NullAway] passing @Nullable parameter 'this.headBranch(name)' where @NonNull is required
        return new RemoteImpl(name, this.headBranch(name));
                                                   ^
    (see http://t.uber.com/nullaway )

Alternatives considered

I'm going to have to check for null... I'm not certain that it's actually possible for the name to be null, doesn't seem likely on a correct config, but maybe someone knows something I don't. I've noticed other objects are comprehensively annotated.

Additional context

No response