odsign: Only try to insert certificate in keyring once.

If this fails, we previously tried to generate a new key, and tried to
insert the cert again. But since we already verified the cert is
well-formed, trying with a new key makes little sense, and in fact
increases boot time on devices that don't support fs-verity.

Bug: 180880942
Test: inspect logs
Change-Id: I6d164489f9a840928ce669e0e38a86148a69c973
1 file changed