fix(util): skip day synthesis for YYYY-MM input

parsePatchLevelValue silently synthesized day=01 when input was
6 chars (YYYY-MM) and caller wanted 8-digit YYYYMMDD. If
ro.vendor.build.security_patch ever returns YYYY-MM on a target
device (older Samsung firmware does), the synthesized day
disagrees with the real bulletin day -- a detection fingerprint.
Return null so getRealDevicePatchLevelInt falls through to
Build.VERSION.SECURITY_PATCH, which is always YYYY-MM-DD.

app/src/main/java/org/matrix/TEESimulator/util/AndroidDeviceUtils.kt

@@ -346,7 +346,9 @@ object AndroidDeviceUtils {
                 6 -> { // YYYYMM
                     val year = normalized.substring(0, 4).toInt()
                     val month = normalized.substring(4, 6).toInt()
-                    if (isLong) year * 10000 + month * 100 + 1 else year * 100 + month
+                    // Synthesizing day=01 from YYYY-MM disagrees with real device bulletins;
+                    // propagate null so callers fall back to a YYYY-MM-DD source.
+                    if (isLong) null else year * 100 + month
                 }
                 else -> null
             }