Make libsquashfs_utils shared

Also rename boot_control_copy away from default.
boot_control_copy isn't a shipping implementation.
boot_control_bcb is the actual default.

Bug: 78793464
Test: compiles
Change-Id: I2bdbcb80605ca396dbfa69b837be381cbcc6e3e7
Merged-In: I2bdbcb80605ca396dbfa69b837be381cbcc6e3e7
(cherry picked from commit 87d6221e37a7c8d579699874b65dd164a6e25251)
2 files changed