Update some fs_mgr/debuggerd to use getpagesize() instead of PAGE_SIZE

Test: th
Bug: 279808236
Change-Id: I9d30cfe19d2b1a7d624cc5425e4315dc6e3b2ad2
diff --git a/debuggerd/crasher/crasher.cpp b/debuggerd/crasher/crasher.cpp
index 6a19878..12ba502 100644
--- a/debuggerd/crasher/crasher.cpp
+++ b/debuggerd/crasher/crasher.cpp
@@ -148,7 +148,7 @@
 noinline void leak() {
     while (true) {
         void* mapping =
-            mmap(nullptr, PAGE_SIZE, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+            mmap(nullptr, getpagesize(), PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
         static_cast<volatile char*>(mapping)[0] = 'a';
     }
 }