remove methods that are only needed by contrib

Author: zeitlinger

javaagent-extension-api/src/main/java/io/opentelemetry/javaagent/extension/internal/ConfigPropertiesUtil.java

@@ -58,11 +58,8 @@ public ConfigProperties resolveInstrumentationConfig(
     if (instrumentationConfig == null) {
       instrumentationConfig = DeclarativeConfigProperties.empty();
     }
-    return resolveConfig(instrumentationConfig.getStructured("java", empty()));
-  }
-
-  public ConfigProperties resolveConfig(@Nullable DeclarativeConfigProperties config) {
     return new DeclarativeConfigPropertiesBridge(
-        config, new ConfigPropertiesTranslator(translationMap, fixedValues));
+        instrumentationConfig.getStructured("java", empty()),
+        new ConfigPropertiesTranslator(translationMap, fixedValues));
   }
 }

javaagent-extension-api/src/main/java/io/opentelemetry/javaagent/extension/internal/DeclarativeConfigPropertiesBridgeBuilder.java

@@ -78,7 +78,7 @@ void shouldUseConfigProviderForDeclarativeConfiguration_noInstrumentationConfig(
       ConfigProperties configProperties =
           new DeclarativeConfigPropertiesBridgeBuilder().resolveConfigProperties(sdkMock);
 
-      assertThat(configProperties.getString("testProperty")).isEqualTo(null);
+      assertThat(configProperties.getString("testProperty")).isNull();
     }
   }
 }