Change to use static constructor to avoid potential resource leaking in...

Change to use static constructor to avoid potential resource leaking in IntrusionDetectionEvent constructor.

Bug: 384055545
Test: atest frameworks/base/services/tests/security/intrusiondetection/src/com/android
/server/security/intrusiondetection/IntrusionDetectionServiceTest.java
Flag: android.security.afl_api
Ignore-AOSP-First: security feature

Change-Id: I57f367cf045527dd1f9800865402991807c4bd79