Rename methods attachJavaagentToCurrentJVM -> attachJavaagentToCurrentJvm

[trask]

The opentelemetry-java and opentelemetry-java-instrumentation repos both have checkstyle rule that would have forced attachJavaagentToCurrentJvm, but we never set up checkstyle in this repo.

Errorprone now has this same check. For now I have suppressed the errorprone violations in #989, but I think we should probably go ahead and rename these public API methods.

opentelemetry-java-contrib/runtime-attach/runtime-attach/src/main/java/io/opentelemetry/contrib/attach/RuntimeAttach.java

Line 17 in 9aa5505

public static void attachJavaagentToCurrentJVM() {

and

opentelemetry-java-contrib/runtime-attach/runtime-attach-core/src/main/java/io/opentelemetry/contrib/attach/core/CoreRuntimeAttach.java

Line 37 in 9aa5505

public void attachJavaagentToCurrentJVM() {

cc @jeanbisutti