Ensure working JVM before enabling Jib actions to avoid hangs

[briandealwis]

Fixes: #5493
Fixes: #5380

Description
macOS provides facades for the common Java executables (e.g., java, javac) that attempt to find and invoke the corresponding commands from a suitable Java VM (normally found in /Library/Java/JavaVirtualMachines). When no Java VM is available, these facades error:

$ java -version
The operation couldn’t be completed. Unable to locate a Java Runtime.
Please visit http://www.java.com for information on installing Java.

But using a Maven Wrapper script (mvnw) instead results in a hang! Tracing through the script shows:

$ sh -x mvnw
...
WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain
+ exec /usr/bin/java -Xmx1g -classpath /Users/bdealwis/Projects/Skaffold/repo-skaffold/integration/examples/jib/.mvn/wrapper/maven-wrapper.jar -Dmaven.home=/Users/bdealwis/Projects/Skaffold/repo-skaffold/integration/examples -Dmaven.multiModuleProjectDirectory=/Users/bdealwis/Projects/Skaffold/repo-skaffold/integration/examples/jib org.apache.maven.wrapper.MavenWrapperMain

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This PR adds a check that a working JVM exists before using Jib.

[codecov]

Codecov Report

Merging #5725 (36bfafa) into master (91c4480) will decrease coverage by 0.03%.
The diff coverage is 35.71%.

@@            Coverage Diff             @@
##           master    #5725      +/-   ##
==========================================
- Coverage   70.70%   70.67%   -0.04%     
==========================================
  Files         428      429       +1     
  Lines       16199    16213      +14     
==========================================
+ Hits        11454    11459       +5     
- Misses       3900     3907       +7     
- Partials      845      847       +2     

Impacted Files	Coverage Δ
pkg/skaffold/build/jib/init.go	83.05% <0.00%> (-4.45%)	⬇️
pkg/skaffold/build/jib/jib.go	69.46% <0.00%> (-1.08%)	⬇️
pkg/skaffold/build/jib/jvm.go	55.55% <55.55%> (ø)

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[MarlonGamez]

Seems good! Just have one question

[MarlonGamez]

Looking good, just noticed a tiny inconsistency

[briandealwis]

I hit hanging-tests again this morning when testing a different change on my M1!

PTAL @MarlonGamez: I tweaked the implementation again and this is now working on all platforms.