fix: readRowSettings use manual readRows settings instead of gapics (#494)

Author: noahdietz

google-cloud-bigtable/src/main/java/com/google/cloud/bigtable/data/v2/stub/EnhancedBigtableStubSettings.java

@@ -546,8 +546,7 @@ private Builder() {
       readRowSettings
           .setRetryableCodes(readRowsSettings.getRetryableCodes())
           .setRetrySettings(
-              baseDefaults
-                  .readRowsSettings()
+              readRowsSettings()
                   .getRetrySettings()
                   .toBuilder()
                   .setTotalTimeout(IDEMPOTENT_RETRY_SETTINGS.getTotalTimeout())