Fix a class cast bug: TupleTagList is not a collection. (#12183)

* Fix a class cast bug: TupleTagList is not a collection.

* Remove unused imports.

* Code changes after running spotless apply.

sdks/java/io/google-cloud-platform/src/main/java/org/apache/beam/sdk/io/gcp/healthcare/HL7v2IO.java

@@ -21,7 +21,6 @@
 import com.google.auto.value.AutoValue;
 import java.io.IOException;
 import java.text.ParseException;
-import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
@@ -275,9 +274,7 @@ public static class Result implements POutput, PInput {
  PCollectionTuple pct;
 
  public static Result of(PCollectionTuple pct) throws IllegalArgumentException {
- if (pct.getAll()
- .keySet()
- .containsAll((Collection<?>) TupleTagList.of(OUT).and(DEAD_LETTER))) {
+ if (pct.getAll().keySet().containsAll(TupleTagList.of(OUT).and(DEAD_LETTER).getAll())) {
  return new Result(pct);
  } else {
  throw new IllegalArgumentException(