debuggerd: add the PAC keys to the tombstones.

Hard to get otherwise if you're trying to debug PAC issues.

Bug: http://b/214314197
Test: treehugger
Change-Id: I2e5502809f84579bf287364e59d6e7ff67770919
diff --git a/debuggerd/proto/tombstone.proto b/debuggerd/proto/tombstone.proto
index a701212..40a942e 100644
--- a/debuggerd/proto/tombstone.proto
+++ b/debuggerd/proto/tombstone.proto
@@ -126,8 +126,9 @@
   repeated BacktraceFrame current_backtrace = 4;
   repeated MemoryDump memory_dump = 5;
   int64 tagged_addr_ctrl = 6;
+  int64 pac_enabled_keys = 8;
 
-  reserved 8 to 999;
+  reserved 9 to 999;
 }
 
 message BacktraceFrame {