[#4181]Improvement: Support setting gradle property skipDockerTests by environment variant

[featherchen]

What changes were proposed in this pull request?

Read the environment variable (if exists) when -PskipDockerTests is not specified.

Why are the changes needed?

Fix: #4181

Does this PR introduce any user-facing change?

No

How was this patch tested?

export SKIP_DOCKER_TESTS=false
./gradlew build
# check docket tests are running

[yuqi1129]

Can you please add some description in the doc

gravitino/docs/how-to-build.md

Lines 28 to 30 in 80e1fc7

	+ Gravitino excludes all Docker-related tests by default. To run Docker related tests, make sure you have installed
	Docker in your environment and set `skipDockerTests=false` in the `gradle.properties` file (or
	use `-PskipDockerTests=false` in the command). Otherwise, all Docker required tests will skip.

[featherchen]

Can you please add some description in the doc

gravitino/docs/how-to-build.md

Lines 28 to 30 in 80e1fc7

	+ Gravitino excludes all Docker-related tests by default. To run Docker related tests, make sure you have installed
	Docker in your environment and set `skipDockerTests=false` in the `gradle.properties` file (or
	use `-PskipDockerTests=false` in the command). Otherwise, all Docker required tests will skip.

Sure, I have updated the doc.

[yuqi1129]

LTGM
@mchades would you like to take a look?

[xunliu]

@yuqi1129 @mchades @featherchen Do we need to keep skipDockerTests propertie in the https://github.com/apache/gravitino/blob/main/gradle.properties#L43 ?

[yuqi1129]

@yuqi1129 @mchades @featherchen Do we need to keep skipDockerTests propertie in the main/gradle.properties#L43 ?

If we do not add it in the gradle.properties, what's the default value of skipDockerTests?

[mchades]

Please add comments to clarify the logic.

[featherchen]

I have add some comments, hope it could help to make the logic clearer.

[featherchen]

@yuqi1129 @mchades @featherchen Do we need to keep skipDockerTests propertie in the main/gradle.properties#L43 ?

If we do not add it in the gradle.properties, what's the default value of skipDockerTests?

Furthermore, if we do not add it, we still need to give the default value of it in related parts of build.gradle.kts

[mchades]

LGTM, do you have more comments? @xunliu @yuqi1129

[yuqi1129]

LGTM, do you have more comments? @xunliu @yuqi1129

I'm okay with the current changes.