Add encryption in incidentd.

+ Sections which require encryption will be encryted on disk.

+ When the sections are requested by clients (e.g., permission controller, report assignee),
  incidentd will decrypte the data.

+ For efficiency, encryption is done ONLY for sections that require encryption.

+ Use Keystore API for key management.

Bug: 131084614
Test: incidentd_test
Change-Id: I84d6b86807ba5bbde1051e847b2df6e79e6b5be5
diff --git a/cmds/incidentd/src/Privacy.cpp b/cmds/incidentd/src/Privacy.cpp
index 386303b..91f0dd3 100644
--- a/cmds/incidentd/src/Privacy.cpp
+++ b/cmds/incidentd/src/Privacy.cpp
@@ -37,6 +37,8 @@
     return NULL;
 }
 
+bool sectionEncryption(int section_id) { return section_id == 3025 /*restricted image section*/; }
+
 static bool isAllowed(const uint8_t policy, const uint8_t check) {
     switch (check) {
         case PRIVACY_POLICY_LOCAL: