Store native libs aligned to PAGE_SIZE

- Add a new flag to zipalign (-p) that page aligns shared
  libraries (zip entries ending with ".so") in the archive.

- Add a new build variable LOCAL_PAGE_ALIGN_SHARED_LIBRARIES
  to turn on this behaviour in zipalign.

- Add a new LOCAL_JNI_SHARED_LIBRARIES_ZIP_OPTIONS to control
  zip behaviour.

Bug: 8076853
Bug: 19330157

Co-Authored-By: Simon Baldwin <simonb@google.com>
Co-Authored-By: Dimitry Ivanov <dimitry@google.com>
Change-Id: I1aa2c039bb2a590ae72f256acc9ba5401c2c59b1
diff --git a/core/clear_vars.mk b/core/clear_vars.mk
index db48bd6..cb32a84 100644
--- a/core/clear_vars.mk
+++ b/core/clear_vars.mk
@@ -20,6 +20,7 @@
 LOCAL_MODULE_CLASS:=
 LOCAL_MODULE_SUFFIX:=
 LOCAL_PACKAGE_NAME:=
+LOCAL_PAGE_ALIGN_JNI_SHARED_LIBRARIES:=
 LOCAL_OVERRIDES_PACKAGES:=
 LOCAL_EXPORT_PACKAGE_RESOURCES:=
 LOCAL_MANIFEST_PACKAGE_NAME:=
@@ -94,6 +95,7 @@
 LOCAL_STRIP_MODULE:=
 LOCAL_JNI_SHARED_LIBRARIES:=
 LOCAL_JNI_SHARED_LIBRARIES_ABI:=
+LOCAL_JNI_SHARED_LIBRARIES_ZIP_OPTIONS:=
 LOCAL_PREBUILT_JNI_LIBS:=
 LOCAL_JAR_MANIFEST:=
 LOCAL_INSTRUMENTATION_FOR:=