Limit the number of CA certificates in a
valid WifiEnterpriseConfig.

Also renames CERTIFICATE_CHAIN_MAX_ELEMENTS
to avoid confusion with the new CA certs limit.

Bug: 276297984
Test: atest WifiEnterpriseConfigTest
Change-Id: I24f0c9bf2f54d73c429cf3bd18704b3a3610f411
2 files changed