Upgrade to 8.8.0

Created using ./update-from-external.sh 8.8.0

m -j32 droid
adb reboot bootloader
fastboot flashall -w
m -j32 cts
cts-tradefed run cts -m CtsTelephonyTestCases -t android.telephony.cts.PhoneNumberUtilsTest
m -j32 libphonenumber-test vogar dx
vogar --timeout 0 \
    --classpath ${ANDROID_BUILD_TOP}/out/target/common/obj/JAVA_LIBRARIES/libphonenumber-test_intermediates/classes.jar \
        com.google.i18n.phonenumbers

Bug: 64924629
Test: see above
Change-Id: Ie7e152ed0d1cb6c39525764a99b9c3eda9be61f7
diff --git a/README.android b/README.android
index 9ba7ea4..7897936 100644
--- a/README.android
+++ b/README.android
@@ -1,5 +1,5 @@
 URL: https://github.com/googlei18n/libphonenumber
-Version: 8.7.1
+Version: 8.8.0
 License: Apache 2
 Description: Google Phone Number Library.