Merge changes I1a855726,Ib7976671,I76e5ee5a into main

* changes:
  keystore: remove misleading error message from AES_gcm_decrypt()
  keystore: eliminate redundant key stretching
  keystore: rename the PBKDF2 functions
diff --git a/keystore2/src/sw_keyblob.rs b/keystore2/src/sw_keyblob.rs
index dc828a0..47ab49f 100644
--- a/keystore2/src/sw_keyblob.rs
+++ b/keystore2/src/sw_keyblob.rs
@@ -216,7 +216,7 @@
     const KEY_BLOB_VERSION: u8 = 0;
 
     /// Hard-coded HMAC key used for keyblob authentication.
-    const LEGACY_HMAC_KEY: &[u8] = b"IntegrityAssuredBlob0\0";
+    const LEGACY_HMAC_KEY: &'static [u8] = b"IntegrityAssuredBlob0\0";
 
     /// Size (in bytes) of appended MAC.
     const MAC_LEN: usize = 8;