otasigcheck: set verification package to com.android.htmlviewer

We need to use something that will always be there and not replaced
by other packages.

Change-Id: Ide942865f284239ae2ae2503005ccc7e8272995c
(cherry picked from commit 7a65923a925b1e816f722997a28cf227cb614d34)
otasigcheck: include multi-digit cert indices

If the cert index is greater than 9, we still want to include it.

Change-Id: I82787e59557ae0bb7f15da16630d2b0afb7cff06
(cherry picked from commit 63c0f71ea432c6b5b6814901c48568df23823ba6)