Deprecate peerServiceMapping (#8088)

Author: trask

api/incubator/src/main/java/io/opentelemetry/api/incubator/config/InstrumentationConfigUtil.java

@@ -23,7 +23,11 @@ public class InstrumentationConfigUtil {
    * .instrumentation.general.peer.service_mapping}, or null if none is configured.
    *
    * @throws DeclarativeConfigException if an unexpected type is encountered accessing the property
+   * @deprecated Peer service mapping was removed from the general instrumentation configuration
+   *     schema. See <a
+   *     href="https://github.com/open-telemetry/opentelemetry-configuration/pull/526">opentelemetry-configuration#526</a>.
    */
+  @Deprecated
   @Nullable
   public static Map<String, String> peerServiceMapping(ConfigProvider configProvider) {
     List<DeclarativeConfigProperties> serviceMappingList =

api/incubator/src/test/java/io/opentelemetry/api/incubator/config/InstrumentationConfigUtilTest.java

@@ -65,6 +65,7 @@ private static ConfigProvider toConfigProvider(String configYaml) {
             new ByteArrayInputStream(configYaml.getBytes(StandardCharsets.UTF_8))));
   }
 
+  @SuppressWarnings("deprecation") // testing deprecated method
   @Test
   void peerServiceMapping() {
     assertThat(InstrumentationConfigUtil.peerServiceMapping(kitchenSinkConfigProvider))