Revert "Revert "Use Rust 1.46.0 prebuilts""

This reverts commit 07f5c7b44099a0d874a03b4fb7e4063ffc1f5a2c.

Re-enable 1.46.0 now that Cargo is working.

Bug: 169246218
Change-Id: I8fb832b18193af6419809d243f910ffb9e63fb4b
1 file changed