termux_step_patch_package: add support for on device patches

Name a patch *.patch.ondevice for it to only be applied when building
on device.

This can be useful if for example a tool for building documentation is
missing on device, or if a tool needed during build (but not runtime)
uses something that triggers selinux, fdsan or some other android
security thing.

scripts/build/termux_step_patch_package.sh

@@ -2,13 +2,22 @@ termux_step_patch_package() {
 	[ "$TERMUX_PKG_METAPACKAGE" = "true" ] && return
 
 	cd "$TERMUX_PKG_SRCDIR"
+	# Suffix patch with ".patch32" or ".patch64" to only apply for
+	# these bitnesses
+	local PATCHES=$(find $TERMUX_PKG_BUILDER_DIR -mindepth 1 -maxdepth 1 \
+			     -name \*.patch -o -name \*.patch$TERMUX_ARCH_BITS)
 	local DEBUG_PATCHES=""
 	if [ "$TERMUX_DEBUG_BUILD" = "true" ]; then
 		DEBUG_PATCHES=$(find $TERMUX_PKG_BUILDER_DIR -mindepth 1 -maxdepth 1 -name \*.patch.debug)
 	fi
-	# Suffix patch with ".patch32" or ".patch64" to only apply for these bitnesses:
+	local ON_DEVICE_PATCHES=""
+	# .patch.ondevice patches should only be applied when building
+	# on device
+	if [ "$TERMUX_ON_DEVICE_BUILD" = "true" ]; then
+		ON_DEVICE_PATCHES=$(find $TERMUX_PKG_BUILDER_DIR -mindepth 1 -maxdepth 1 -name \*.patch.ondevice)
+	fi
 	shopt -s nullglob
-	for patch in $TERMUX_PKG_BUILDER_DIR/*.patch{$TERMUX_ARCH_BITS,} $DEBUG_PATCHES; do
+	for patch in $PATCHES $DEBUG_PATCHES $ON_DEVICE_PATCHES; do
 		echo "Applying patch: $(basename $patch)"
 		test -f "$patch" && sed \
 			-e "s%\@TERMUX_APP_PACKAGE\@%${TERMUX_APP_PACKAGE}%g" \