Keycloak.json property not consistent with other Pravega Keycloak Integrations

[maddisondavid]

Problem description
The Rust client uses the pravega_client_auth_keycloak property for the location of the keycloak.json file, however, this is not consistent with existing Pravega Keycloak integrations such as the Java Pravega Keycloak plugin Keycloak plugin https://github.com/pravega/pravega-keycloak which use KEYCLOAK_SERVICE_ACCOUNT_FILE.

The result is that systems configured with the environment for Pravega must be modified in order to use the Python bindings.

• https://github.com/pravega/pravega-keycloak/blob/bb81cb4ad2e5208f8c48c954d9b52c742b16214b/client/src/main/java/io/pravega/keycloak/client/KeycloakConfigResolver.java#L40-L41

Problem location

pravega-client-rust/config/src/lib.rs

Line 164 in b57b2ea

let path = ret_val.get(AUTH_KEYCLOAK_PATH).expect("get keycloak json file");

Suggestions for an improvement
The Rust client should also support the KEYCLOAK_SERVICE_ACCOUNT_FILE as well as pravega_client_auth_keycloak in order to be consistent.