Clears direct_buffer_address_ when init recording fails on Android.

Avoids hitting a DCHECK in AudioRecordJni::OnCacheDirectBufferAddress()
when first init attempt has failed and we try again.

Bug: b/69434512
Change-Id: I4396ba22981d9258d6d72188bad66104255f19cf
Reviewed-on: https://webrtc-review.googlesource.com/31842
Reviewed-by: Alex Glaznev <glaznev@webrtc.org>
Commit-Queue: Henrik Andreassson <henrika@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#21218}

modules/audio_device/android/audio_record_jni.cc

@@ -126,6 +126,7 @@ int32_t AudioRecordJni::InitRecording() {
   int frames_per_buffer = j_audio_record_->InitRecording(
       audio_parameters_.sample_rate(), audio_parameters_.channels());
   if (frames_per_buffer < 0) {
+    direct_buffer_address_ = nullptr;
     ALOGE("InitRecording failed!");
     return -1;
   }