tree 563048545ecb7ab0b2ed49c132e0f201a5bac966
parent ad93a191e789449c6891b6728f1ef36a6b366d3b
author Kangping Dong <wgtdkp@google.com> 1705391025 +0800
committer Kangping Dong <wgtdkp@google.com> 1705392473 +0800

[Thread] add error code ERROR_UNKNOWN for forward compatibility

This is per the go/android-api-guidelines#return-error:
```
Make sure your chosen error handling option gives you the
flexibility to introduce new error types in the future. For
@IntDef, that means including an OTHER or UNKNOWN value - when
returning a new code, you can check the caller's targetSdkVersion
to avoid returning an error code the application doesn't know
about. For exceptions, have a common superclass that your
exceptions implement, so that any code that handles that type will
also catch and handle subtypes.
```

Bug: 320403080
Change-Id: I2ee663b75107dac6d84fa697f449fa0424128fde