Provide OS and system properties to python addons

[peak3d]

Description

using the xbmc module 2 new functions are available:

• getOsName() -> returns the name of the os kodi is running
• getSystemPropertyString -> returns device dependent system properties

Motivation and Context

I'm working on an addon which requires some system properties to build a token.

How Has This Been Tested?

Sample script which includes print(xbmc.getOsName())

Types of change

• Bug fix (non-breaking change which fixes an issue)
• Clean up (non-breaking change which removes non-working, unmaintained functionality)
• Improvement (non-breaking change which improves existing functionality)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that will cause existing functionality to change)
• Cosmetic change (non-breaking change that doesn't touch code)
• None of the above (please explain below)

[ronie]

could you add a few examples here?
it's not clear to me what 'system properties' are...

also, is this android only?

[DaveTBlake]

All OS? Also if addons/Python interface gets this then so should JSON API :)

[enen92]

I am not sure if I'm able to review this.
Which system properties are we talking about? Do you mean those properties that are injected from the JVM and get available in the app context only in android?

For the os name method, I'm wondering if it really belongs in our python API. Can't the same be achieved from the python bultin platform module? (e.g. platform.system()?)

For the property method I agree with ronie. It needs better documentation to explain which properties we're trying to obtain and in which platforms the method returns usable data. I'm also not sure if ifdefing there is the best approach. Sure the implications are small but if every method did the same we end up with some sort of spaguetti. Maybe a Platform() class in xbmc module which is then inserted from the build system would be a better alternative? Or is that too much work?

[CastagnaIT]

i can try to explain something

method getSystemPropertyString:
is platform dependent, in this PR is implemented only for android,
see if def: https://github.com/xbmc/xbmc/pull/17265/files#diff-2f806c83b24e5dd8d8a26076af9d511eR779

This method (on android) is a sort of wrapper to query android build prop info, can be used as:
my_value = getSystemPropertyString("ro.product.model")
then my_value contains the product model value example "Nexus 6"

If used on other type of OS, should return null value
(Of course, it can also be implemented later to obtain information from other operating systems)

method getOsName:
returns the name of the operating system used

[jenkins4kodi]

@peak3d this needs a rebase