Updated ADB & Fastboot Files

Changelog:

adb:

* Fixed zero length packet sends for macOS (issuetracker: 208675141).
* Addressed unstable connectivity (MacBook high speed cable): frequent adb disconnects.
* Improved error message for adb push with insufficient number of arguments.

fastboot:

* Improved flashing: flashall will now skip reboots to userspace if it can.
* Fixed zero length packet sends for macOS (issuetracker: 208675141).
* Fixed flashing recovery.img resulting in wrong AVB footer.