Add 'ANDROID_API_MIN' target property to set Android Target MIN API

Also add a 'CMAKE_ANDROID_API_MIN' variable to set the property
default.  Teach the VS generator to write the MIN API value into
Nsight Tegra project files.
Merge topic 'vs-nsight-tegra-min-api' into next

eeaa25e5 Add 'ANDROID_API_MIN' target property to set Android Target MIN API