Unexpected handling of lines with less than 100 characters

I have some quite large sql multiline string and when one line is over 100 characters it will re-format it onto 2 lines. While I believe this is the correct behaviour to split this long line, it also re-formats all of the other lines of the String which I don't think should happen as they are under 100 characters long, therefore I think this is a bug.

NB: Because of https://github.com/google/google-java-format/issues/566 you can only see this happening using the jar on the command line as per the example below:

before - unformatted file:
```
package x;

public class test {

static final String MY_SQL_QUERY =
"SELECT "
+ " customer_id AS customer_id, "
+ " customer_id AS customer_id, "
+ " customer_id AS customer_id, "
+ " customer_id AS customer_id, "
+ " customer_id AS customer_id, "
+ " l.some_really_long_column_name AS some_really_looooooooooooooooooooong_column_name, "
+ " customer_id AS customer_id, "
+ " customer_id AS customer_id, ";

public test() {
int x=1;if(x==1){x=2;}else{x=3;}
}

}
```

apply google java formatting:
```
/tmp $ java -version
openjdk version "11.0.9" 2020-10-20
OpenJDK Runtime Environment AdoptOpenJDK (build 11.0.9+11)
OpenJDK 64-Bit Server VM AdoptOpenJDK (build 11.0.9+11, mixed mode)
/tmp $ cksum ~/lib/google-java-format-1.9-all-deps.jar
2002751029 3404610 ~/lib/google-java-format-1.9-all-deps.jar
/tmp $ java -jar ~/lib/google-java-format-1.9-all-deps.jar ./test.java
```
after - formatted by google java formatter:
```
package x;

public class test {

static final String MY_SQL_QUERY =
"SELECT customer_id AS customer_id, customer_id AS customer_id, "
+ " customer_id AS customer_id, customer_id AS customer_id, "
+ " customer_id AS customer_id, l.some_really_long_column_name AS"
+ " some_really_looooooooooooooooooooong_column_name, customer_id AS"
+ " customer_id, customer_id AS customer_id, ";

public test() {
int x = 1;
if (x == 1) {
x = 2;
} else {
x = 3;
}
}
}
```

Expected - this is what I think google java formatter should do:
```
package x;

public class test {

static final String MY_SQL_QUERY =
"SELECT "
+ " customer_id AS customer_id, "
+ " customer_id AS customer_id, "
+ " customer_id AS customer_id, "
+ " customer_id AS customer_id, "
+ " customer_id AS customer_id, "
+ " l.some_really_long_column_name "
+ "AS some_really_looooooooooooooooooooong_column_name, "
+ " customer_id AS customer_id, "
+ " customer_id AS customer_id, ";

public test() {
int x = 1;
if (x == 1) {
x = 2;
} else {
x = 3;
}
}
}
```