Allow development with JDK 16 + add build with multiple JDK versions

[artursouza]

Describe the proposal

Running unit tests with JDK 16 fails. We should make it pass with JDK 16.

Action items:

• Fix code to allow unit tests to run with JDK 16
• Change Dapr Build to run against multiple JDKs: 11, 13, 15, 16

Tests run: 362, Failures: 0, Errors: 228, Skipped: 0

[INFO] ------------------------------------------------------------------------
[INFO] Reactor Summary for dapr-sdk-parent 1.2.0-SNAPSHOT:
[INFO] 
[INFO] dapr-sdk-parent .................................... SUCCESS [  9.167 s]
[INFO] dapr-sdk-autogen ................................... SUCCESS [ 15.819 s]
[INFO] dapr-sdk ........................................... FAILURE [ 14.405 s]
[INFO] dapr-sdk-actors .................................... SKIPPED
[INFO] dapr-sdk-springboot ................................ SKIPPED
[INFO] dapr-sdk-examples .................................. SKIPPED
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  41.957 s
[INFO] Finished at: 2021-08-13T11:53:23-07:00
[INFO] ------------------------------------------------------------------------

[artursouza]

@mthmulders Please, comment with /assign to get this assigned to you.

[mthmulders]

/assign

[mthmulders]

I'm afraid /assign didn't do the trick, so I'll manually assign to myself.

[mthmulders]

... if only I could :-(

[mthmulders]

@artursouza It seems the /assign never does the trick, but I can't assign issues to myself either. Is there some kind of bot that's supposed to take care of it maybe?

[artursouza]

We have this bot in most repos, but not in this one yet. I am manually assigning. Regardless, GitHub only allows issues to be assigned if the user has interacted with the issue or is part of the org.