Reformat ui dockerfile. (#5724)

docker/ui/Dockerfile.ui

 # Licensed to the Apache Software Foundation (ASF) under one
-    # or more contributor license agreements.  See the NOTICE file
-    # distributed with this work for additional information
-    # regarding copyright ownership.  The ASF licenses this file
-    # to you under the Apache License, Version 2.0 (the
-    # "License"); you may not use this file except in compliance
-    # with the License.  You may obtain a copy of the License at
-    #
-    #     http://www.apache.org/licenses/LICENSE-2.0
-    #
-    # Unless required by applicable law or agreed to in writing, software
-    # distributed under the License is distributed on an "AS IS" BASIS,
-    # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-    # See the License for the specific language governing permissions and
-    # limitations under the License.
-
-    FROM openjdk:8u181-jdk-stretch
-
-    ENV DIST_NAME=apache-skywalking-apm-bin \
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+FROM openjdk:8u181-jdk-stretch
+
+ENV DIST_NAME=apache-skywalking-apm-bin \
     JAVA_OPTS=" -Xms256M " \
     SW_OAP_ADDRESS="127.0.0.1:12800" \
     SW_TIMEOUT="20000"
 
-    COPY "$DIST_NAME.tar.gz" /
+COPY "$DIST_NAME.tar.gz" /
 
-    RUN set -ex; \
+RUN set -ex; \
     tar -xzf "$DIST_NAME.tar.gz"; \
     rm -rf "$DIST_NAME.tar.gz"; \
     rm -rf "$DIST_NAME/config"; \
     rm -rf "$DIST_NAME/bin"; rm -rf "$DIST_NAME/oap-libs"; rm -rf "$DIST_NAME/agent"; \
     mv "$DIST_NAME" skywalking;
 
-    WORKDIR skywalking
+WORKDIR skywalking
 
-    COPY docker-entrypoint.sh .
-    COPY logback.xml webapp/
+COPY docker-entrypoint.sh .
+COPY logback.xml webapp/
 
-    EXPOSE 8080
+EXPOSE 8080
 
-    ENTRYPOINT ["bash", "docker-entrypoint.sh"]
\ No newline at end of file
+ENTRYPOINT ["bash", "docker-entrypoint.sh"]
\ No newline at end of file