Compile obd for running on mobile and call by java on android

[neocarmack]

Currently lack of document on compiling mobile node and steps to invock by java side on android. We don't need docker on mobile devices.

The doc must include:

1. System requiroment. Is the "root" necessary. Maybe a tested device list.
2. Compilation enviroment preparation: for example: android sdk, gomobile version, makefile, etc.
3. Commands to compile: correct output, solutions for possible errors.
4. Package for java developers.
5. Step-by-step java example code.

[wxf4150]

already have a docs at: https://github.com/omnilaboratory/lnd/blob/obd/mobile/README.md
need some update.

@healergyl will add java-android operation

[healergyl]

asdasdasdasd

[wxf4150]

i have update the doc for obd-android-bind.aar libarary build.