Adding new GSI public keys

Adding two new public keys for R-Developer-GSI and S-Developer-GSI,
respectively.

Bug: 149805495
Test: m r-developer-gsi.avbpubkey
Test: m s-developer-gsi.avbpubkey

Change-Id: Iaa7521ef40b94f13fe3c9c61d276678f47c60b98
Merged-In: Iaa7521ef40b94f13fe3c9c61d276678f47c60b98
(cherry picked from commit b697d47eb38b2dcfa545dfddb163927fc7f56900)
3 files changed