qmake: Fix android_16kb_pages check for qmake projects

The qtConfig() check in android.prf used an incorrect feature name
with a QT_FEATURE_ prefix.

This caused an error when configuring any qmake project for Android:

 Project ERROR: Could not find feature QT_FEATURE_android_16kb_pages.

Fix the name of the feature in the qtConfig().

Even with the fixed name, the check would never succeed because we
never exported the feature, so we didn't have a
'QT.core.enabled_features' entry for it in the qt_lib_core.pri file.

To ensure we export the feature, mark the it as a CMake PRIVATE
feature (so we don't touch the public qconfig.h header in a patch
release), and then add a qt_feature_config() call to create an entry
in the public QT_CONFIG variable as well as QT.core.enabled_features.

Amends f174e2a
Amends 48dcf5c

Pick-to: 6.10 6.8
Fixes: QTBUG-144166
Change-Id: I96505798ad32f0d31175be7d064e15fca7ddd6c7
Reviewed-by: Joerg Bornemann <joerg.bornemann@qt.io>
(cherry picked from commit cfad21c)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

Author: alcroito

configure.cmake

@@ -1306,12 +1306,17 @@ qt_feature("coverage"
     CONDITION QT_FEATURE_coverage_gcov
 )
 
-qt_feature("android_16kb_pages"
+# Mark the feature as PRIVATE because we want it to be exported, but we don't want modifications
+# in the public qconfig.h header in a patch release.
+qt_feature("android_16kb_pages" PRIVATE
     LABEL "Using 16KB page sizes in Android"
     CONDITION ANDROID AND (((CMAKE_ANDROID_NDK_VERSION VERSION_GREATER_EQUAL "25.0.0"))
                           AND ((CMAKE_ANDROID_ARCH_ABI STREQUAL "arm64-v8a") OR
                               (CMAKE_ANDROID_ARCH_ABI STREQUAL "x86_64")))
 )
+# The feature is saved into the public QT_CONFIG var in the qt_lib_core.pri file, to ensure it's
+# available automatically for testing with qtConfig() in all user projects.
+qt_feature_config("android_16kb_pages" QMAKE_PUBLIC_QT_CONFIG)
 
 qt_configure_add_summary_build_type_and_config()
 qt_configure_add_summary_section(NAME "Build options")

mkspecs/features/android/android.prf

@@ -36,7 +36,7 @@ build_pass|if(single_android_abi:!single_arch) {
                        else:TARGET = lib$${TARGET}_$${QT_ARCH}.so
             }
             QMAKE_LFLAGS += -Wl,-soname,$$shell_quote($$TARGET)
-            qtConfig(QT_FEATURE_android_16kb_pages) {
+            qtConfig(android_16kb_pages) {
                 QMAKE_LFLAGS += -Wl,-z,max-page-size=16384
             }
             android_install {