SystemUI: Add keep rule for VendorServices constructor

This constructor is looked up reflectively and should be kept explicitly. Future versions of R8 in full mode will no longer implicitly keep VendorServices.<init> when VendorServices is kept.

Bug: 356344563
Bug: 373579455
Test: existing
Change-Id: I07d2b4c576b3e01a76875d7c02327fa5acab4660
1 file changed