fix: the type name returned by Spanner is 'real'

Author: olavloite

src/main/resources/com/google/cloud/spanner/jdbc/postgresql/DatabaseMetaData_GetColumns.sql

@@ -21,7 +21,7 @@ SELECT TABLE_CATALOG AS "TABLE_CAT", TABLE_SCHEMA AS "TABLE_SCHEM", TABLE_NAME A
            WHEN DATA_TYPE LIKE 'bytea' THEN -2
            WHEN DATA_TYPE = 'date' THEN 91
            WHEN DATA_TYPE = 'double precision' THEN 8
-           WHEN DATA_TYPE = 'single precision' THEN 7
+           WHEN DATA_TYPE = 'real' THEN 7
            WHEN DATA_TYPE = 'bigint' THEN -5
            WHEN DATA_TYPE = 'numeric' THEN 2
            WHEN DATA_TYPE LIKE 'character varying' THEN -9
@@ -35,7 +35,7 @@ SELECT TABLE_CATALOG AS "TABLE_CAT", TABLE_SCHEMA AS "TABLE_SCHEM", TABLE_NAME A
            WHEN DATA_TYPE LIKE 'bytea' THEN 10485760
            WHEN DATA_TYPE = 'date' THEN 10
            WHEN DATA_TYPE = 'double precision' THEN 15
-           WHEN DATA_TYPE = 'single precision' THEN 15
+           WHEN DATA_TYPE = 'real' THEN 15
            WHEN DATA_TYPE = 'bigint' THEN 19
            WHEN DATA_TYPE = 'numeric' THEN 15
            WHEN DATA_TYPE LIKE 'character varying' THEN CHARACTER_MAXIMUM_LENGTH
@@ -45,15 +45,15 @@ SELECT TABLE_CATALOG AS "TABLE_CAT", TABLE_SCHEMA AS "TABLE_SCHEM", TABLE_NAME A
        0 AS "BUFFER_LENGTH",
        CASE
            WHEN DATA_TYPE LIKE 'double precision' THEN 16
-           WHEN DATA_TYPE LIKE 'single precision' THEN 16
+           WHEN DATA_TYPE LIKE 'real' THEN 16
            WHEN DATA_TYPE LIKE 'numeric' THEN 16383
            ELSE NULL
            END AS "DECIMAL_DIGITS",
        CASE
            WHEN DATA_TYPE LIKE 'bigint' THEN 10
            WHEN DATA_TYPE LIKE 'numeric' THEN 10
            WHEN DATA_TYPE LIKE 'double precision' THEN 2
-           WHEN DATA_TYPE LIKE 'single precision' THEN 2
+           WHEN DATA_TYPE LIKE 'real' THEN 2
            ELSE NULL
            END AS "NUM_PREC_RADIX",
        CASE

src/test/java/com/google/cloud/spanner/jdbc/it/ITJdbcPgDatabaseMetaDataTest.java

@@ -148,7 +148,7 @@ private Column(
       Arrays.asList(
           new Column("colint64", Types.BIGINT, "bigint", 19, null, 10, false, null),
           new Column("colfloat64", Types.DOUBLE, "double precision", 15, 16, 2, false, null),
-          new Column("colfloat32", Types.REAL, "single precision", 15, 16, 2, false, null),
+          new Column("colfloat32", Types.REAL, "real", 15, 16, 2, false, null),
           new Column("colbool", Types.BOOLEAN, "boolean", null, null, null, false, null),
           new Column("colstring", Types.NVARCHAR, "character varying", 100, null, null, false, 100),
           new Column(