Support marvell-armhf dpkg cache and the azp check.
Waiting for merging PR #9381 to 202012 branch, so only azp template change in this PR.
Move the VS build to a new stage BuildVS, change the Test stage only depending on BuildVS, running the BuildVS and the other platform's build in parallel. The Test stage do not has dependency on the marvel-armhf build, reduce the overall build time caused by longer build time of marvel-armhf build.
Why I did it
Fix the boolean value case sensitive issue in Azure Pipelines
When passing parameters to a template, the "true" or "false" will have case sensitive issue, it should be a type casting issue.
To fix it, we change the true/false to yes/no, to escape the trap.
Support to override the job groups in the template, so PR build has chance to use different build parameters, only build simple targets. For example, for broadcom, we only build target/sonic-broadcom.bin, the other images, such as swi, debug bin, etc, will not be built.
