16k: soong: Add flag Device_page_size_agnostic

The flag Device_page_size_agnostic will determine whether
AOSP is kernel page size agnostic or not.

Test: source build/envsetup.sh
      lunch aosp_raven_64-userdebug
      m -j$(nproc)
      cat out/soong/build.aosp_raven_64.ninja | grep TARGET_PAGE_SIZE_AGNOSTIC
Bug: 289419664
Change-Id: I0604db64a3b44db63f93773be003cdd44e0a867b
diff --git a/android/variable.go b/android/variable.go
index 1c81f3c..f07ab56 100644
--- a/android/variable.go
+++ b/android/variable.go
@@ -95,6 +95,10 @@
 			Cflags []string
 		}
 
+		Device_page_size_agnostic struct {
+			Cflags []string `android:"arch_variant"`
+		} `android:"arch_variant"`
+
 		Override_rs_driver struct {
 			Cflags []string
 		}
@@ -275,6 +279,7 @@
 	Safestack                    *bool    `json:",omitempty"`
 	HostStaticBinaries           *bool    `json:",omitempty"`
 	Binder32bit                  *bool    `json:",omitempty"`
+	Device_page_size_agnostic    *bool    `json:",omitempty"`
 	UseGoma                      *bool    `json:",omitempty"`
 	UseRBE                       *bool    `json:",omitempty"`
 	UseRBEJAVAC                  *bool    `json:",omitempty"`
@@ -529,6 +534,7 @@
 		Safestack:                    boolPtr(false),
 		TrimmedApex:                  boolPtr(false),
 		Build_from_text_stub:         boolPtr(false),
+		Device_page_size_agnostic:    boolPtr(false),
 
 		BootJars:     ConfiguredJarList{apexes: []string{}, jars: []string{}},
 		ApexBootJars: ConfiguredJarList{apexes: []string{}, jars: []string{}},