Fixes a detection vector where the simulator could be identified by comparing certificate signatures from different API calls.
Previously, the simulator would re-patch and re-sign a certificate on-the-fly for both `generateKey` and `getKeyEntry` calls. Due to the non-deterministic nature of ECDSA signing, this resulted in different signatures for the same certificate, which is a detectable anomaly not present in a real TEE.
This is resolved by caching the patched certificate chain after its initial creation in `KeyMintSecurityLevelInterceptor`. The `getKeyEntry` hook in `Keystore2Interceptor` now retrieves the chain from this cache, guaranteeing that subsequent calls return a byte-for-byte identical certificate.
Cache cleanup logic was also integrated into key deletion and clearing functions to maintain state consistency.
