Enlarge SYSTEM_LAST_KMSG truncated size from 96KB to 192KB

- This is for userdebug build only
- Target to improve ramdump-less debugging for All of Pixel devices
- Max bootloader logs size is 45KB and will be appended to last kernel
  log end
- Totally enlarge last kernel logs size from (96-45)KB to < (192-45)KB
  => extra inserted size: header(521B), truncated signature(14B), footer(43B)
     SYSTEM_LAST_KMSG + header(521B) + truncated signature(14B) + footer(43B) = 196608B(192KB)
     and actual SYSTEM_LAST_KMSG is 196030 < 192KB

Bug: 145574030
Change-Id: I7b5921e1f01433c7aa27e564ab28181d0a4d0b31