vars: Use fbpacktool for unpacking bootloader.img on Tensor pixels

All Pixels modem.img: fbpack version 1
QCOM Pixels bootloader.img: fbpack version 1
Tensor Pixels bootloader.img: fbpack version 2

Test:
export WORK_DIR=/some/dir/with/factory/images
source vendor/lineage/vars/pixels
for d in ${devices[@]}; do lineage/scripts/pixel/firmware.sh $d; done
for d in ${devices[@]}; do git -C vendor/google/$d status; done

Co-authored-by: Chirayu Desai <chirayudesai1@gmail.com>
Change-Id: Ic1990f75a6be515e5d91d65e3ddf88b8e0c90001

vars/bluejay

@@ -18,8 +18,7 @@ device_repos=(
   device/google/bluejay
 )
 
-# Need OTA zip for firmware, not supported by image_unpacker yet
-readonly needs_ota=true
+readonly fbpk_version="v2"
 
 # Updated semi-manually via pixel/update-any-var.sh
 

vars/cheetah

@@ -19,8 +19,7 @@ device_repos=(
   device/google/pantah
 )
 
-# Need OTA zip for firmware, not supported by image_unpacker yet
-readonly needs_ota=true
+readonly fbpk_version="v2"
 
 # Updated semi-manually via pixel/update-any-var.sh
 

vars/lynx

@@ -18,8 +18,7 @@ device_repos=(
   device/google/lynx
 )
 
-# Need OTA zip for firmware, not supported by image_unpacker yet
-readonly needs_ota=true
+readonly fbpk_version="v2"
 
 # Updated semi-manually via pixel/update-any-var.sh
 

vars/oriole

@@ -18,8 +18,7 @@ device_repos=(
   # common repos in raven
 )
 
-# Need OTA zip for firmware, not supported by image_unpacker yet
-readonly needs_ota=true
+readonly fbpk_version="v2"
 
 # Updated semi-manually via pixel/update-any-var.sh
 

vars/panther

@@ -18,8 +18,7 @@ device_repos=(
   # common repos in cheetah
 )
 
-# Need OTA zip for firmware, not supported by image_unpacker yet
-readonly needs_ota=true
+readonly fbpk_version="v2"
 
 # Updated semi-manually via pixel/update-any-var.sh
 

vars/raven

@@ -19,8 +19,7 @@ device_repos=(
   device/google/raviole
 )
 
-# Need OTA zip for firmware, not supported by image_unpacker yet
-readonly needs_ota=true
+readonly fbpk_version="v2"
 
 # Updated semi-manually via pixel/update-any-var.sh