CachedAppOptimizer: Remove PAGE_MASK usage

Android V will support page size agnostic targets. The bionic macro
PAGE_MASK won't be defined for the agnostic targets. For the CachedAppOptimizer,
the PAGE_MASK macro will be replaced by ~(getpagesize() - 1).

Bug: 296512786
Test: source build/envsetup.sh
      lunch aosp_cf_arm64_phone_pgagnostic
      m
Change-Id: Ic4c50dcb5e4eb4a8ce6460df240340868c76f252

services/core/jni/com_android_server_am_CachedAppOptimizer.cpp

@@ -51,6 +51,9 @@ using android::base::WriteStringToFile;
 using android::meminfo::ProcMemInfo;
 using namespace android::meminfo;
 
+static const size_t kPageSize = getpagesize();
+static const size_t kPageMask = ~(kPageSize - 1);
+
 #define COMPACT_ACTION_FILE_FLAG 1
 #define COMPACT_ACTION_ANON_FLAG 2
 
@@ -61,7 +64,7 @@ using android::base::unique_fd;
 #define ASYNC_RECEIVED_WHILE_FROZEN (2)
 #define TXNS_PENDING_WHILE_FROZEN (4)
 
-#define MAX_RW_COUNT (INT_MAX & PAGE_MASK)
+#define MAX_RW_COUNT (INT_MAX & kPageMask)
 
 // Defines the maximum amount of VMAs we can send per process_madvise syscall.
 // Currently this is set to UIO_MAXIOV which is the maximum segments allowed by
@@ -224,7 +227,6 @@ public:
 // process_madvise on failure
 int madviseVmasFromBatch(unique_fd& pidfd, VmaBatch& batch, int madviseType,
                          uint64_t* outBytesProcessed) {
-    static const size_t kPageSize = getpagesize();
     if (batch.totalVmas == 0 || batch.totalBytes == 0) {
         // No VMAs in Batch, skip.
         *outBytesProcessed = 0;