New methods proposal

[vrunoa]

@jlipps encourage me to write a proposal for adding new methods for mobile specs. It would be good to start providing new endpoints for common functionalities available on every mobile device but hasnt been implemented yet; such as battery states, level and external communication factors which can trigger actions on applications that users would like to test. This idea came up because we already started implementing it for android emulators and is probably going to be used cross-platform, so we should get everybody's opinion before adding new endpoints. What do you guys think ?

[vrunoa]

@jlipps @shs96c any feedback on this?

[CLAassistant]

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