A law enforcement officer in one state is NOT a law enforcement officer in any other state absent the fresh pursuit doctrine, in which case the officer from the foreign state must be in full uniform.
Therefore, your law enforcement credential from Nevada would not function as a concealed carry permit in California, and unless you have an actual concealed permit in the state of CA (or a Nevada Permit if CA has a reciprocity agreement), you would be unlawfully carrying the firearm without a permit. For LEOSA to kick in, you have to be able to prove the weapon was shipped through an instrument of interstate commerce, otherwise LEOSA is inoperable under the 10th amendment. The burden is on you to prove that LEOSA is in fact operable under your particular case, because the legal presumption for purposes of probable cause is that LEOSA does not effect provisions of state law. (i.e. it is presumed by default that the weapon was not in fact shipped in interstate commerce absence compelling evidence to the contrary.)