Fix toybox_vendor dependencies again.

Fix toybox_vendor dependencies again.

toybox_vendor now links to other libraries as shared libraries.
This allows toybox_vendor to use the "vendor" version of these libraries
(in particular, liblog and libselinx_vendor).

Test: mma -j
Test: m -j, flash, boots
Test: `adb shell /vendor/bin/restorecon /dev/null` shows error message
Test: `adb shell /vendor/bin/getprop -Z' shows error message
Test: mma -j BOARD_VNDK_VERSION=current

Bug: 63537547
Bug: 62886649

Change-Id: Ia55cc50bd4dbf14ac3a7fdc27be5974074741a26