Allow RSA 4096 key in package verification

The RSA_verify sitll works for 4096 bits keys. And we just
need to loose the check on modulus.

Sample commands to generate the key & package:
1. openssl genrsa -out keypair.pem 4096
2. openssl pkcs8 -topk8 -inform PEM -outform DER -nocrypt \
   -in keypair.pem -out private.pk8
3. openssl req -new -x509 -key keypair.pem -out public.x509.pem \
   -days 365
4. java -Djava.library.path=prebuilts/sdk/tools/linux/lib64 -jar \
   prebuilts/sdk/tools/lib/signapk.jar -w public.x509.pem private.pk8 \
   unsigned.zip signed.zip

Bug: 129163830
Test: unit tests pass
Change-Id: I5a5ff539c9ff1955c02ec2ce4b17563cb92808a4