chrono: enable "serde" feature am: b439b3182b am: 0bd811eecd am: 9ba9d2600c am: aace0241b7 am: dc2acc78c4

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/chrono/+/2513913

Change-Id: I697929edaf4e88981e882f81e091e3b800f22ba0
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>