It's not just $HOME/.AndroidStudio2.2, it might also be
.AndroidStudioPreview2.3, or .AndroidStudioFooBar1.7, or whatever.
Made the Version parser less throw-happy, and relaxed the directory name
checks to allow for the above.
Fixes#8353.
* Fix bug parsing Gradle version.
Version from pub_semver requires versions of the format X.Y.Z. Gradle
doesn't follow semantic versioning, though, so version parsing would
fail on versions like '3.2'. Fixed by writing a custom Version class.
Also removed a check for apksigner when building Gradle-based projects.
Fixes#8298
