identity: Add multi-document presentation support.

This new IPresentationSession interface enables an application to do a
multi-document presentation, something which isn't possible with the
existing API. As a practical example of this consider presenting both
your Mobile Driving License and your Vaccination Certificate in a single
transaction.

Bug: 197965513
Test: New CTS tests and new screen in CtsVerifier
Change-Id: I11712dca35df7f1224debf454731bc17ea9bfb37
diff --git a/identity/aidl/default/libeic/EicOps.h b/identity/aidl/default/libeic/EicOps.h
index d4fcf0e..aa26e62 100644
--- a/identity/aidl/default/libeic/EicOps.h
+++ b/identity/aidl/default/libeic/EicOps.h
@@ -141,6 +141,10 @@
 // String length, see strlen(3).
 size_t eicStrLen(const char* s);
 
+// Locate a substring, see memmem(3)
+void* eicMemMem(const uint8_t* haystack, size_t haystackLen, const uint8_t* needle,
+                size_t needleLen);
+
 // Memory compare, see CRYPTO_memcmp(3SSL)
 //
 // It takes an amount of time dependent on len, but independent of the contents of the
@@ -151,6 +155,12 @@
 // Random number generation.
 bool eicOpsRandom(uint8_t* buf, size_t numBytes);
 
+// Creates a new non-zero identifier in |id|.
+//
+// Is guaranteed to be non-zero and different than what is already in |id|.
+//
+bool eicNextId(uint32_t* id);
+
 // If |testCredential| is true, returns the 128-bit AES Hardware-Bound Key (16 bytes).
 //
 // Otherwise returns all zeroes (16 bytes).
@@ -295,6 +305,8 @@
                              int verificationTokenSecurityLevel,
                              const uint8_t* verificationTokenMac, size_t verificationTokenMacSize);
 
+// Also see eicOpsLookupActiveSessionFromId() defined in EicSession.h
+
 #ifdef __cplusplus
 }
 #endif