Changes in this update:
**Enhancements**
* Added support for [Bluetooth Interface 2.0](https://developer.amazon.com/docs/alexa/alexa-voice-service/bluetooth.html). This interface adds support for multiple simultaneous connections to Bluetooth peripherals.
* Added support for [Audio Focus Manager Library (AFML) Multi Activity](https://developer.amazon.com/docs/alexa/avs-device-sdk/sdk-interaction-model.html). This interface enhances the behavior of a device so it can handle more than one Activity per Channel.
* Added the `obfuscatePrivateData` logging method to help remove certain data from logs.
* Updated `MediaPlayerObserverInterface` to include metadata about playback states.
* Added SDK extension point. You can integrate CMake projects into the SDK without cloning those projects into a subdirectory.
**Bug fixes**
* Fixed Mac/OSX issue that caused an unresponsive Sample App when not connected to the internet.
* Fixed issue that prevented sample app from exiting various states.
* Fixed `UIManager` issue that caused an error in the logs when the device with built without the wake word enabled.
* Fixed volume issue that caused timers to ascend in volume when setting up ascending alarms.
* Fixed alert volume issue that caused any changes to the alert volume to notify observers.
* Fixed EQ issue where changes to the EQ band levels didn't notify observers.
* Fixed Bluetooth bug that caused short notification sounds from a connected phone to stop audio playback on the device.
**Known Issues**
* Build errors can occur on the Raspberry Pi due to incorrect linking of the atomic library. A suggested workaround is to add the following `set(CMAKE_CXX_LINK_FLAGS "${CMAKE_CXX_LINK_FLAGS} -latomic")` to the top most CMake file.
* The WebVTT dependency required for `captions` isn't supported for Windows/Android.
* Exiting from the setting option takes you back to the Options Menu directly. It doesn't provide a message to indicate that you're back in the main menu.
* Failing Unit Tests and AIP Unit tests are disabled on Windows
* `AudioInputProcessor` unit tests don't build on Windows when with the `-DCMAKE_BUILD_TYPE=DEBUG` cmake parameter.
* Music playback history isn't displayed in the Alexa app for certain account and device types.
* When using Gnu Compiler Collection 8+ (GCC 8+), `-Wclass-memaccess` triggers warnings. You can ignore these, they don't cause the build to fail.
* Android error `libDefaultClient.so not found` might occur. Resolve this by upgrading to ADB version 1.0.40.
* If a device loses a network connection, the lost connection status isn't returned though local TTS.
* ACL encounters issues if it receives audio attachments but doesn't consume them.
* Media streamed through Bluetooth might abruptly stop. To restart playback, resume the media in the source application or toggle next/previous.
* If a connected Bluetooth device is inactive, the Alexa app might indicates that audio is playing.
* The Bluetooth agent assumes that the Bluetooth adapter is always connected to a power source. Disconnecting from a power source during operation isn't yet supported.
* When using some products, interrupted Bluetooth playback might not resume if other content is locally streamed.
* `make integration` isn't available for Android. To run Android integration tests, manually upload the test binary and input file and run ADB.
* Alexa might truncate the beginning of speech when responding to text-to-speech (TTS) user events. This only impacts Raspberry Pi devices running Android Things with HDMI output audio.
* A reminder TTS message doesn't play if the sample app restarts and loses a network connection. Instead, the default alarm tone plays twice.
* `ServerDisconnectIntegratonTest` tests are disabled until they are updated to reflect new service behavior.
* The `DirectiveSequencerTest.test_handleBlockingThenImmediatelyThenNonBockingOnSameDialogId` test fails intermittently.
Keith Huang
Alexandre Mendonca
Michael Woo
Caleigh Minshall