Remove Unicode whitespace before AM/PM in the status bar

The regression is introduced in Android 14 with ICU 72 when \u202f
is used in the time format for en-US.

UCharacter.isUWhitespace is a better way to determine Unicode whitespace
characters than the characters used in the java language as in JLS 3.6,
because the time format comes from the ICU following the Unicode / CLDR spec.

Flag: NA
Bug: 312903894
Test: Verified that MAGIC1 is inserted before \u202f
Test: Inspected the TextView.mText via https://google.github.io/web-hv
Change-Id: I7b660b94c6ef75dbe96be8bcd2b074c8edd73ba7