Set "run_cargo": false, "min_sdk_version": "29" when importing crates.

min_sdk_version should only ever be set to 29, and it's safer to just
set it for everything by default. Not running cargo (and just parsing
Cargo.toml) is usually safe, and much faster.

Test: treehugger
Change-Id: Id768de91540953cc2d51cd21fe3315284bd96196