### What changes were proposed in this pull request?
The current docker image used by Kubernetes is `openjdk:8-alpine`. It was not supported and was removed with the commit 3eb0351b20 (diff-f95ffa3d1377774732c33f7b8368e099).
This PR proposes to move to a supported docker image.
### Why are the changes needed?
I think there are at least two reasons:
1. According to the commit, Alpine/musl is not officially supported by the OpenJDK project.
2. As no more OpenJDK 8 Alpine images, new JDK updates including security fixes
, are not applied to it. See below:
```
docker run -it --rm openjdk:8-alpine java -version
openjdk version "1.8.0_212"
OpenJDK Runtime Environment (IcedTea 3.12.0) (Alpine 8.212.04-r0)
OpenJDK 64-Bit Server VM (build 25.212-b04, mixed mode)
```
```
docker run -it --rm openjdk:8-jdk-slim java -version
openjdk version "1.8.0_222"
OpenJDK Runtime Environment (build 1.8.0_222-b10)
OpenJDK 64-Bit Server VM (build 25.222-b10, mixed mode)
```
### Does this PR introduce any user-facing change?
Yes. This changes the base docker image of Spark.
### How was this patch tested?
Existing tests.
Closes#26037 from viirya/SPARK-28938.
Authored-by: Liang-Chi Hsieh <viirya@gmail.com>
Signed-off-by: Dongjoon Hyun <dhyun@apple.com>
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