Deprecate prebuilts/misc/linux-x86/lz4/lz4

Replace prebuilts/misc/linux-x86/lz4/lz4 with external/lz4.

Test: \
  development/gsi/build_with_kernel/fetch_kernel.sh \
  development/gsi/build_with_kernel/repack_kernels.sh
Bug: 205492988

Change-Id: Ic22e6ea7cc68b45761b963ea3c41fd099ea29bc9
2 files changed