downgrading buildToolsVersion in hopes of getting CI to run

1 job for navigation in 3 minutes and 20 seconds (queued for 2 seconds)
Status Name Job ID Coverage
  Build
failed assembleDebug #4851

00:03:20

 
Name Stage Failure
failed
assembleDebug Build
* Get more help at https://help.gradle.org

Deprecated Gradle features were used in this build, making it incompatible with Gradle 6.0.
Use '--warning-mode all' to show the individual deprecation warnings.
See https://docs.gradle.org/5.1.1/userguide/command_line_interface.html#sec:command_line_warnings

BUILD FAILED in 2m 4s
16 actionable tasks: 16 executed
ERROR: Job failed: exit code 1