Memtrack HAL: Remove MemtrackType::NUM_TYPES

Remove NUM_TYPES from MemtrackType enum, since this can cause conflicts
if the enum changes.

Use enum_range to iterate the MemtrackType enum.

Bug: 179432507
Test: atest VtsHalMemtrackTargetTest
Change-Id: Iadad3e0547c1c2f6aaf0f55a2d50e4c625a909e0
diff --git a/memtrack/aidl/default/Memtrack.cpp b/memtrack/aidl/default/Memtrack.cpp
index 000b25c..49a6582 100644
--- a/memtrack/aidl/default/Memtrack.cpp
+++ b/memtrack/aidl/default/Memtrack.cpp
@@ -26,7 +26,8 @@
     if (pid < 0) {
         return ndk::ScopedAStatus(AStatus_fromExceptionCode(EX_ILLEGAL_ARGUMENT));
     }
-    if (type < MemtrackType::OTHER || type >= MemtrackType::NUM_TYPES) {
+    if (type != MemtrackType::OTHER && type != MemtrackType::GL && type != MemtrackType::GRAPHICS &&
+        type != MemtrackType::MULTIMEDIA && type != MemtrackType::CAMERA) {
         return ndk::ScopedAStatus(AStatus_fromExceptionCode(EX_UNSUPPORTED_OPERATION));
     }
     _aidl_return->clear();