Improve logic of getting java version

[chenrujun]

Plugin name and version

Plugin name: com.microsoft.azure:azure-spring-apps-maven-plugin
Version: 1.14.0
Goal: config

Plugin configuration in your pom.xml

Nothing

Expected behavior

1. Detect the Java version specified in pom.xml
2. Let use input Java version manually without -DadvancedOptions.
   Just like existing logic of handle app name

I need something like:

Input Java version (17):

Where 17 is detected by pom. Here is an example of Java version in pom.xml:

<properties>
  <java.version>17</java.version>
</properties>

Actual behavior

1. Java version can only be configured with -DadvancedOptions
2. The java version is always 11 it can not be detected by pom.xml Here is the screenshot:

Steps to reproduce the problem