Make smallvec available to product and vendor am: 48d46cce35 am: 1d11037c6f am: cf55601445 am: 6a99587c55

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/smallvec/+/2476461

Change-Id: Ic4fc38833c58245ccc7b25249f2f0ede69a94d65
Signed-off-by: Automerger Merge Worker <[email protected]>