speech: Null-check service connection before usage

In SpeechRecognizer handleStartListening, handleStopMessage and
handleCancelMessage, there is a null-check before calling
the service’s methods. The same check is now added to
handleCheckRecognitionSupport and handleTriggerModelDownload.

Bug: 282013412
Test: atest CtsVoiceRecognitionTestCases
Change-Id: I506282779e02747f8904cf9cbbdbc3ce135ee2b7

core/java/android/speech/SpeechRecognizer.java

@@ -812,7 +812,7 @@ public class SpeechRecognizer {
             Intent recognizerIntent,
             Executor callbackExecutor,
             RecognitionSupportCallback recognitionSupportCallback) {
-        if (!maybeInitializeManagerService()) {
+        if (!maybeInitializeManagerService() || !checkOpenConnection()) {
             return;
         }
         try {
@@ -831,7 +831,7 @@ public class SpeechRecognizer {
             Intent recognizerIntent,
             @Nullable Executor callbackExecutor,
             @Nullable ModelDownloadListener modelDownloadListener) {
-        if (!maybeInitializeManagerService()) {
+        if (!maybeInitializeManagerService() || !checkOpenConnection()) {
             return;
         }