mach: android install/run: infer adb path from SDK dir
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Infer Android `adb` path from SDK directory in environment variables.
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- [x] `./mach test-tidy` does not report any errors
- [x] These changes fix#20219 (github issue number if applicable).
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- [x] These changes do not require tests because it is a build script change
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Currently we check `if not (osmesa_path and glapi_path)` after using
`path.join`. It seems we actually want to check whether
`find_dep_path_newest` returns something, because if calls to that
function fail, we'll instead get an error from `path.join` about
`NoneType` not having attribute `endswith` (it expects a string), which
preempts this check.
Support for Android armv7 and aarch64 target triples
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Support for Android armv7 and aarch64 target triples in python build scripts (build + packaging)
`--android` build parameter works as always (arm-linux-androideabi still the default)
`./mach build --release --android`
New compilation modes for android
`./mach build --release --target=arm-linux-androideabi`
`./mach build --release --target=armv7-linux-androideabi`
`./mach build --release --target=aarch64-linux-android`
See https://github.com/servo/servo/issues/11921. When all crates are ready we'll switch default android compilations to` armv7-linux-androideabi` target triple.
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- [x] `./mach test-tidy` does not report any errors
- [ ] These changes fix #__ (github issue number if applicable).
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- [x] There are tests for these changes OR
- [ ] These changes do not require tests because _____
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