Upgrade rust/crates/cexpr to 0.6.0 am: 417a5cbdb1 am: 6e902fa055 am: 3f23e9d263

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/cexpr/+/2137713

Change-Id: I2d129aaf5390e904af5282fef0845119e1bc2fc6
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>