devel/android-tools-adb: update to 5.1.1.r4

Other changes include:

• Add option to use bash(1) completion from Debian
• Install protocol and implementation documentation

Changes: https://android.googlesource.com/platform/system/core/+log/android-5.0.0_r7..android-5.1.1_r4/adb
Differential Revision: https://reviews.freebsd.org/D2862
Obtained from: r389153, r389235, r389239
Approved by: kevlo (maintainer)