"INSTALL_NON_MARKET_APPS" depreciated as of Android API 26

[r-tx]

The method MVT is using for checking if non market based installs are allowed was depreciated API 26 (android 8) and results is mvt always giving a warning.

8.0 changes

The value of the legacy setting INSTALL_NON_MARKET_APPS is now always 1. To determine whether an unknown source can install apps using the package installer, you should instead use the return value of canRequestPackageInstalls().

New method canRequestPackageInstalls is available for >= API 26 devices and should be per app.

It would be useful to take into account the api level when reporting this setting so as not to give misleading results