devel/android-tools-{adb,fastboot}: update to 7.1.0.r4

Changes: https://android.googlesource.com/platform/system/core/+log/android-7.0.0_r1..android-7.1.0_r4/adb
Changes: https://android.googlesource.com/platform/system/core/+log/android-7.0.0_r1..android-7.1.0_r4/fastboot