[BUG] Gradle run not working

[ryanbogan]

After merging #687, the command ./gradlew run no longer works for extensions/SDK that are using the integration test framework. The root cause of this is the use of a plugin-descriptor.properties file that is expected from the OpenSearch gradle plugin. It is not possible to use this file for extensions, so we need to find an alternative to make sure ./gradlew run works.

[dbwiddis]

See also #175 which should be resolved when setting this up.