idmap2: add signature policy

Handles the new signature policy for overlayable resources.

Bug: 119402606

Test: idmap2_tests target

Change-Id: I7961e04a879c40c240ed9097bb510addb8b56680
diff --git a/cmds/idmap2/tests/RawPrintVisitorTests.cpp b/cmds/idmap2/tests/RawPrintVisitorTests.cpp
index a5588c3..7ec13ed 100644
--- a/cmds/idmap2/tests/RawPrintVisitorTests.cpp
+++ b/cmds/idmap2/tests/RawPrintVisitorTests.cpp
@@ -52,8 +52,8 @@
 
   ASSERT_NE(stream.str().find("00000000: 504d4449  magic\n"), std::string::npos);
   ASSERT_NE(stream.str().find("00000004: 00000001  version\n"), std::string::npos);
-  ASSERT_NE(stream.str().find("00000008: dd53ca29  target crc\n"), std::string::npos);
-  ASSERT_NE(stream.str().find("0000000c: a71ccd77  overlay crc\n"), std::string::npos);
+  ASSERT_NE(stream.str().find("00000008: d513ca1b  target crc\n"), std::string::npos);
+  ASSERT_NE(stream.str().find("0000000c: 8635c2ed  overlay crc\n"), std::string::npos);
   ASSERT_NE(stream.str().find("0000021c: 00000000  0x7f010000 -> 0x7f010000 integer/int1\n"),
             std::string::npos);
 }