Android: Add Gradle.Properties element

[mortend]

This UXL element makes it possible to output project-specific information in the gradle.properties file.

Example.uxl:

    <Require Gradle.Properties>
        <![CDATA[
org.gradle.jvmargs=-Xmx1536M \
    --add-exports=java.base/sun.nio.ch=ALL-UNNAMED \
    --add-opens=java.base/java.lang=ALL-UNNAMED \
    --add-opens=java.base/java.lang.reflect=ALL-UNNAMED \
    --add-opens=java.base/java.io=ALL-UNNAMED \
    --add-exports=jdk.unsupported/sun.misc=ALL-UNNAMED
        ]]>
    </Require>