Sign timezone APEX with the correct certificate

Add 'certificate' property to set the certificate name.

Test: m com.android.tzdata
jarsigner -verify -verbose -certs out/target/product/blueline/system/apex/com.android.tzdata.apex shows
...
X.509, CN=com.android.tzdata, OU=Android, O=Android, L=Mountain View, ST=California, C=US

Change-Id: Iea7cbe16f993e76fc0539099202f203cfa255c7e
2 files changed