Allow vendor-init-readable for sys.boot_completed and dev.bootcomplete

Bug: 75987246
Test: succeeded builing and tested with taimen
Change-Id: I2d8bc91c305e665ed9c69459e51204117afb3eee
Merged-In: I2d8bc91c305e665ed9c69459e51204117afb3eee
(cherry picked from commit ac2e4cce)

public/property_contexts

@@ -115,6 +115,8 @@ tombstoned.max_tombstone_count u:object_r:exported3_default_prop:s0 exact int
 vold.post_fs_data_done u:object_r:exported2_vold_prop:s0 exact int
 
 # vendor-init-readable|vendor-init-actionable
+dev.bootcomplete u:object_r:exported3_system_prop:s0 exact bool
+sys.boot_completed u:object_r:exported3_system_prop:s0 exact bool
 sys.retaildemo.enabled u:object_r:exported3_system_prop:s0 exact int
 
 # vendor-init-settable|vendor-init-actionable